Annual Meeting 2014: Abstracts of Poster Presentations

* indicates a poster eligible for the Council Poster Prize.
Underlined author denotes designated presenter.

Fossil Fruits of the London Clay: A New Insight from X-Ray Analysis

^*Neil F. Adams^1,2, Mary J. Andrew¹, Margaret E. Collinson^1,3, Steven R. Manchester⁴, Gregory W. Stull⁴, Fabiany Herrera^4,5, Paul Kenrick³ and Dan Sykes⁶

¹Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, U.K.
²Department of Geography, Royal Holloway University of London, Egham, Surrey, TW20 0EX, U.K.
³Department of Earth Sciences, Natural History Museum, London, SW7 5BD, U.K.
⁴Florida Museum of Natural History and Department of Biology, University of Florida, Gainesville, Florida 32611, U.S.A.
⁵Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, Illinois 60022, U.S.A.
⁶Imaging and Analysis Centre, Natural History Museum, London, SW7 5BD, U.K.

The diverse fossil flora of the London Clay Formation in South East England has been interpreted as a paratropical rainforest fringed by coastal mangroves, which grew during the Early Eocene Climatic Optimum (EECO) between 52-49Ma.

The London Clay collection at the Natural History Museum contains pyritized fruits and seeds of flowering plants that were first described using light microscopy nearly 200 years ago and are now stored in silicone oil to prevent further pyrite decomposition. Physical sectioning is inappropriate for their holotypes. Non-destructive, X-ray micro-computed tomography (micro-CT) was applied to specimens in silicone oil to obtain hitherto inaccessible internal information with minimal risk.

Holotypes from twenty-one species of Icacinaceae (mainly lianas) and four species of Anacardiaceae (the cashew family) were scanned. A taxonomic re-evaluation of these historic specimens, using previously unseen characters, has, in almost every case, confirmed and resolved their affinities with modern relatives and confirmed the London Clay’s diversity of tropical taxa. Digital visualisation of otherwise hidden pyrite infills has enabled fossil internal casts to be linked to external fruit morphology. Even badly cracked holotypes have yielded taxonomically useful information and have highlighted the potential of micro-CT in monitoring vulnerable fossils.

The Taxonomy, Taphonomy and Tomography of Miocene Cissus from Kenya: The First Record of Vitaceae in Africa

^*Neil F. Adams^1,2, Margaret E. Collinson^1,3, Selena Y. Smith⁴, Marion K. Bamford⁵ and Federica Marone⁶

¹Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, U.K.
²Department of Geography, Royal Holloway University of London, Egham, Surrey, TW20 0EX, U.K.
³Department of Earth Sciences, Natural History Museum, London, SW7 5BD, U.K.
⁴Museum of Paleontology and Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109, U.S.A.
⁵Evolutionary Studies Institute and School of Geosciences, University of the Witwatersrand, P. Bag 3, Wits 2050, Johannesburg, South Africa.
⁶Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland.

Surface ornamentation on mineralized fossil seeds from the Kenyan Miocene Hiwegi Formation is closely comparable to that on seeds of modern African Cissus. These fossils are the first record of Cissus and the Vitaceae (grape vine family) in Africa.  Previously the seeds had been assigned to the Menispermaceae - a completely different plant group. We aim to confirm our new identification, understand the previous taxonomic error, and determine the clades of Cissus to which the fossils belong.

Forty-two modern Cissus fruits were scanned using synchrotron radiation X-ray tomographic microscopy (SRXTM). The high-resolution images revealed complex layering of different tissue types and thicknesses in the fruit walls and seed coats, parts of which are very thin and delicate. All these layers would respond in different ways to decomposition and fossilization processes. Furthermore, all the seeds are characterized by deep ventral infolds, which could easily become infilled and hence obscured by minerals during fossilization. We conclude that taphonomic factors led to the previous incorrect identification and obscured the fossils’ true affinity. “Virtual taphonomy” [the digital removal or infill of structures to mimic fossilization processes] is currently being applied to the modern Cissus to produce digital fossils for direct comparison with actual fossils.

Phosphatization in the Ediacaran: a taphonomic model for the Biskopås Formation of southern Norway

^*Peter W Adamson¹

¹University of Cambridge

Detailed taphonomic analysis is now recognized as a prerequisite for any palaeobiological analysis, particularly in the case of problematic fossils. Reinvestigation of phosphorite pebbles from the early Ediacaran Biskopas Formation in southern Norway reveals a previously unrecorded diversity of large acanthomorphic acritarchs from two distinct taphonomic windows; most significant being apatite permineralization. Co-occurring with these apatite permineralized specimens are pyritized sphaeromorphic and filamentous microfossils and a second occurrence of Doushantuo-type preservation – early precipitation of isopachous and botryoidal apatite. Petrographic analysis of the Biskopas phosphorites suggests the microfossils were deposited into a primary phosphatic sediment, rather than a secondarily phosphatized carbonate sediment. A mould of the external morphology was created during very early hardground formation, encasing the microfossil, which was rapidly followed by permineralization of the cell lumen. This is revealed by several examples where the cell wall has shrank inwards from the external mould prior to permineralization. Fe-rich clay occasionally precipitates within the microfossil instead of apatite, often preventing permineralization of the wall. This model indicates that Biskopas microfossils are preserved within their primary depositional environment and enables new palaeoenvironmental and taphonomic comparisons with the Doushantuo that may shine new light on this enigmatic microbiota.

New eukaryotic microfossils from the Mesoproterozoic Ruyang Group, China

^*H. Agic¹, M. Moczydlowska¹ and L. Yin²

¹Department of Earth Sciences, Palaeobiology, Uppsala University, Sweden
²Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, China

Siliciclastics of the Ruyang Group in the Shanxi Province, North China Craton, encompassing the latest Paleoproterozoic and Mesoproterozoic, have yielded a diverse assemblage of eukaryotic and prokaryotic organic-walled microfossils.  

Samples from several beds in the lower Bedajian Formation (Ruyang) were macerated in HF acid, and the extracted fossils were studied with light and scanning electron microscopy. Specimens include bacterial sheaths, and acritarchs with elaborate wall structure: Dictyosphaera macroreticulata, Shuiyousphaeridium macroreticulatum and Tappania plana morphotypes, as well as several new, unnamed taxa including both spheromorphs and acanthomorphs.

Recently, the age of deposition of the Ruyang Group and the overlying Luoyou Group has been constrained to 1750 to 1400 Ma, older than previously thought. This pushes back the age constraint on the first appearance of complex eukaryotic morphologies in the fossil record.

Novel cell morphologies in the Ruyang biota include vesicles with velutinous outer membrane, thin hirsute processes and membranous tube-like extensions, as well as internal bodies.

While the subgroup biological affinity of the new Ruyang microfossils is unclear, the sum of evidence from size and morphology to co-occurrence with members of diverged eukaryotic lineages like Shuiyousphaeridium (Chloroplastida), positions 

Revisiting the King collection: palaeogeographical significance of the Permian brachiopods from England

^*B. Allen¹, D. A. Harper¹ and H.A. Armstrong¹

¹Durham University

William King’s classic description and analysis of the Permian Fossils of England (Palaeontographical Society Monographs, 1850) contains detailed descriptions and beautiful illustrations of the Brachiopoda, forming the basis for much further research on these faunas from elsewhere in the World. Despite a substantial, unpublished thesis (A. Logan, Durham University, 1962) and a field guide to Permian fossils of the region (N.T.J. Hollingworth and T.H. Pettigrew, Palaeontological Association, Field Guides to Fossils, 1988) this key fossil group has received little subsequent attention. Re-evaluation and re-illustration of King’s brachiopod type and figured material in the National University of Ireland, Galway has helped establish a database for the distribution of the fauna within the North of England and elsewhere in the Zechstein province. Comparisons with coeval faunas from the Arctic and Tethyan Province have confirmed the unique characteristics of the Zechstein Brachiopoda and, regionally, helped understand the palaeoecology of these brachiopod-dominated assemblages in the Northeast of England prior to major environmental changes in the Zechstein Basin.

Testing the evidence for gill slits in an Ordovician echinoderm

^*Nidia Alvarez Armada¹, Imran A. Rahman² and Christopher B. Cameron³

¹School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen’s Road, Bristol BS8 1RJ, UK, Current address: School of Biological, Earth and Environmental Science, University College Cork, North Mall, Cork, Ireland
²School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen’s Road, Bristol BS8 1RJ, UK
³Département de sciences biologiques, Université of Montréal, C.P. 6128, Succ. Centre-ville, Montréal, Quebec H3C 3J7, Canada

Phylogenetic bracketing of the living deuterostome clades suggests that their latest common ancestor was a bilaterally symmetrical animal with pharyngeal gill slits. If this hypothesis is accurate, we might expect to see these characters in early fossil representatives of the phyla. Here, we evaluate the evidence for gill slits in the Ordovician echinoderm Lagynocystis pyramidalis. X-ray micro-tomography was used to characterise the internal anatomy of Lagynocystis and extant deuterostomes (two hemichordates and one cephalochordate). In addition, we imaged the internal respiratory structures (hydrospires) of two Devonian blastoids using phase-contrast synchrotron radiation X-ray tomographic microscopy. Finally, we utilised computational fluid dynamics to simulate functional performance in Lagynocystis and the modern deuterostomes. Tomographic imaging confirms the presence of a complex of internal bars in Lagynocystis, which is similar in both form and size, to the gill bars of the modern deuterostomes; however, individual folds in the hydrospires of blastoids are also similar to these bars. Computer modelling of fluid flow suggests that gill bars in modern deuterostomes affect water flow rather differently to the internal bars of Lagynocystis, implying an alternative function. Based on this, we find no support for the long-standing hypothesis that the fossil echinoderm Lagynocystis possessed internal pharyngeal bars.

Apparent diversity drop after the Cryogenian (Sturtian) ice age in southwestern Mongolia – a product of extinction or taphonomy?

^*Ross P Anderson¹, Francis A Macdonald², Nicholas J Tosca³, Tanja Bosak⁴, Uyanga Bold² and Derek E G Briggs¹

¹Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT, 06511, USA
²Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA, 02138, USA
³Department of Earth Sciences, University of Oxford, South Park Road, Oxford, OX1 3AN, UK
⁴Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA

Few fossils have been described from sequences between the Sturtian (~720-660 Ma) and Marinoan (~640-635 Ma) “snowball Earth” ice ages despite paleontologists documenting a Neoproterozoic radiation of the crown-group eukaryotes in the ~150 Myr prior to this interval. The paucity of fossils in rocks of this age has been interpreted as the result of an extinction associated with the proliferation of biologically unfavorable environments. Recent fossil discoveries in the Zavkhan basin of southwestern Mongolia have begun to populate the fossil record of the nonglacial interlude. Here we explore the contribution of taphonomy to diversity patterns during the Neoproterozoic, in particular the role of clay minerals in the preservation of the Mongolian fossils. We report preliminary stratigraphic records from the Taishir Formation (Tsagaan-Olom Group, Mongolia) of fossil abundance based on petrographic thin-sections and rock macerations, in addition to bulk-rock clay mineralogy analysed by x-ray diffraction. Clay mineral assemblages vary from berthierine (lowest ~150 m) through to talc (middle ~25 m) and kaolinite (highest ~225 m) coincident with shifts in fossil abundance. Future work will use samples from shale and chert horizons to explore facies bias, and will address any metamorphic effects on clay mineral assemblages.

Cretaceous polychelidan lobster larva: evolutionary implications.

^*Denis Audo¹, Joachim T. Haug², Carolin Haug², Pierre Abi Saad³, Gilles Petit⁴, Jean-Paul Saint Martin⁴ and Sylvain Charbonnier⁴

¹Université de Rennes 1, EA 7316 'Biodiversité et Gestion des Territoires'
²University of Munich (LMU) Department of Biology II, Functional Morphology group
³Memory of Time
⁴UMR 7207 (CR2P) MNHN/UPMC, Département Histoire de la Terre, Muséum national d’Histoire naturelle, Paris, France

The ontogeny of some extant crustacean groups can be characterized by an abrupt metamorphosis at the transition between the planktonic larva and the benthic adult. Such metamorphoses are for instance well-documented for mantis shrimps (Stomatopoda), slipper and spiny lobsters (Palinurida) and polychelid lobsters (Polychelidae). In this latter group, the zoea and megalopa instars, called eryone icus lar vae, are characterized by an inflated, balloon-like carapace covered by abundant spines. Such larvae have never been discovered in the fossil record. Examination of small individuals of fossil Polychelida (the group containing Polychelidae) suggests that the ontogeny of many fossil species did not include eryoneicus larvae nor metamorphosis. Recently, two small fossil decapod crustaceans were discovered in the famous Lagerstätte of Hadjoula (Lebanon, Cenomanian). These specimens are clearly juvenile Polychelida. Both possess a carapace spinier and less flattened than other juvenile fossil polychelidans. They also preserve a developed rostrum usually occurring in earliest eryoneicus stages. These characters suggest they represent an early form of eryoneicus larva. They nevertheless differ from eryoneicus larva by the shape of their carapace, less inflated than extant eryoneicus. Their unique combination of characters therefore suggests eryoneicus larvae evolved gradually from a juvenile more similar in morphology to the adult.

Development of the Elgin Museum Recognised Collection for education and scientific use

^*Susan R Beardmore¹

¹Elgin Museum, 1 High Street, Elgin, Moray, IV30 1EQ

The Elgin Museum houses a Scottish Government ‘Recognised’ Collection of Devonian, Permian and Triassic vertebrate fossils, sourced in Moray during the early-mid 19^th Century. In the past the collection has been associated with Murchison, Sedgewick, Miller, Buckland, Agassiz, Lyell and Huxley among others, who visited the area and/or figured specimens in literature still relevant today. The fossils have also contributed to discussions on tetrapod evolution, dicynodont phylogeny and the radiation of early dinosaurs. The importance of the collection is further raised by the fact that many of the quarries sourcing these unique fossils are now closed or inaccessible, meaning new examples are not likely to be recovered. The Recognised Collection has therefore undergone extensive development to allow better access to the fossils, and use as an education and scientific resource. The identification and condition of specimens has been checked, storage re-organised systematically (age; location) and documentation thoroughly revised. The work has bought to light many interesting and well-preserved fish and reptile specimens of considerable historical significance for use in subsequent displays. The success, and difficulties, of the development are also described so that other museums undergoing similar changes, now or in the future, can benefit from our experience.

Cenozoic hydrocarbon seep molluscs from the Caribbean region

^*Jordan Bestwick¹, Crispin T.S. Little², Fiona L. Gill² and Steffen Kiel³

¹School of Biology, University of Leeds, Leeds, UK
²School of Earth and Environment, University of Leeds, Leeds, UK
³Georg-August Universität Göttingen, GZG, Geobiology Group, Goldschmidtstr. 3, 37077 Göttingen, Germany

Hydrocarbon seeps are sites along deep continental margins where hydrocarbon-rich fluids flow onto the seafloor. Modern seeps are numerically dominated by fauna with symbiotic chemoautotrophic bacteria, including bivalves and vestimentiferan tubeworms, and also by grazing gastropods. Fossil seeps date back to the Devonian and there have been substantial changes in faunal assemblages through the Phanerozoic. Eocene-Miocene seep assemblages from Barbados and Trinidad were originally described in earlier preliminary papers. Since additional specimens are now available, and knowledge of Mesozoic and early Cenozoic seep faunas has increased, reinvestigation of Caribbean seep fossils offers new insights into their evolutionary history. Over 450 specimens were described, comprising at least 20 bivalve and 18 gastropod species, including 5 and 11 new species respectively. Most of the described species show either a distinctive Caribbean character or affinities to coeval Pacific seep molluscs, and seem to have disappeared after the Miocene. Surprisingly few modern seep molluscs in the Caribbean/Gulf of Mexico have a pre-Pliocene fossil record in this region. It is thus tempting to speculate the closure of the Isthmus of Panama played a role in shaping the modern seep fauna in the Caribbean.

Jurassic Halloween: Discovery of exocysts on echinoid spines from the Callovian of Israel

^*Tomasz Borszcz¹, Mark A. Wilson² and Marcin Binkowski³

¹Department of Marine Ecology, Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, POLAND
²Department of Geology, The College of Wooster, Wooster, Ohio 44691, USA
³X-ray Microtomography Lab, Institute of Computer Science, University of Silesia, 75 Pułku Piechoty 1, 41-500 Chorzów, POLAND

Calcified cysts provide direct evidence of parasitic interactions in ancient communities, thus offering unique insights into the evolution of biotic interactions. Until now parasites were found only on echinoid tests (coronae) and as internal infestations of spines. We discovered the first exocysts on echinoid spines from the Matmor Formation (Callovian of Israel). They represent the oldest infestation of spines. These “pumpkin masks” are located close to the spine base and their morphology (number of orifices, size, shape and spatial distribution) differs from all known echinoid infestations, including those reported on other Jurassic cidaroid hosts as well as on the irregular echinoid Collyrites. This new find demonstrates that (i) the location of the cysts on echinoids is not linked with parasite feeding preferences (settlement is random), (ii) parasitism was facilitated by epidermis-free spines, which is a common feature of cidaroids, (iii) parasitism intensity on echinoids was extremely low at that time, even in tropical settings, (iv) neither cyst abundance, geographic occurrence nor other ecological parameters followed a latitudinal gradient, (v) cyst size and abundance has not changed over geologic time, and (vi) in contrast to modern distributions, cyst-dwelling parasites proliferated in shallow water, mid-Mesozoic calcite seas.

Variations in seasonality of productivity over the last 20 kyr in the bathyal NE Atlantic using foraminifera

^*Curtis Bracher¹

¹University of Plymouth

Benthic foraminifera (shelled protists) (>63 μm) from the last 20 kyr were analysed from Ocean Drilling Program (ODP) Hole 980B (55°29.094’N, 14°42.137’W, 2168 m water depth), NE Atlantic Ocean. During the last 20 kyr, changes occurred in their accumulation rates, species composition and diversity. It has been shown that in the area today seasonal inputs of phytodetritus (phytoplankton detritus) to the ocean floor following the spring bloom in surface water primary productivity exert a strong influence on benthic foraminifera and other organisms. Benthic foraminifera respond rapidly to the presence of phytodetritus arriving on the sea floor by quickly colonising and feeding on the detritus, reproducing rapidly and building up large populations. In the area of ODP Hole 980B, the main ‘phytodetritus species’ are Eponides pusillus, Nonionella iridea and Cassidulina obtusa. These ‘phytodetritus species’ are abundant in ODP Hole 980B during the last 20 kyr and variations in their abundance are interpreted as resulting from changes in the seasonality of productivity.

Periwinkles graze holes in Pacific oyster shells

Gerhard C. Cadée¹

¹R. Neth. Inst. Sea Research (NIOZ)

The taphonomic explanation of holes in shells is not always easy. They may be produced by predators (boring gastropods, smashing stomatopods), abrasion during tumbling in the surf zone, transport over a sandy bottom and sandblasting. Can microboring organisms, living in shells of epibenthic mollusks and empty shells on the sea bottom, also cause holes in shells as sometimes suggested? I observed that the help of grazing herbivores is needed. In the Wadden Sea, gastropods Littorina littorea feeding on microborers make holes in the upper valves of intertidal Pacific oysters Crassostrea gigas. Endolithic lichens Pyrenocollema halodytes heavily infest these oysters. During life, oysters will add new shell material on the inside, but this stops after death. When the oysters remain attached, Littorina continues grazing the still living lichens. This results in holes and finally total destruction of the oyster shells.

Don’t hold your breath: new constraints on atmospheric ρO₂ during Romer’s Gap

^*David Carpenter¹, John Marshall¹, David Beerling² and Charles Wellman²

¹University of Southampton
²University of Sheffield

Following the End Devonian Mass Extinction tetrapods disappear almost completely from the fossil record for some 15 million years – a phenomenon known as Romer’s Gap. Latest Devonian tetrapods were aquatic and equipped with a variable number of digits, front and back; following their reappearance they were fully terrestrialised and five-fingered. This apparent gap therefore covers a major turning point in vertebrate evolution, but the cause of the hiatus remains unclear. One common hypothesis, in part based on Palaeozoic atmospheric models, is that atmospheric oxygen levels were low during Romer’s Gap and this drove tetrapod evolution.  However, such models are highly complex and incorporate a number of assumptions which are difficult to test; disagreement over how to incorporate these in a realistic way has led to widely diverging outputs that are difficult to reconcile.

A high-resolution Famennian - Viséan record of wildfire frequency, based on the abundance of microscopic charcoal (inertinite) as dispersed organic matter in sedimentary rocks, is providing new insights into biosphere flammability, and hence an independent constraint on ρO₂ during this critical interval. Results thus far indicate no significant suppression of wildfire activity, suggesting that reduced atmospheric ρO₂ is not a viable explanation for Romer’s Gap.

Palaeobiogeography of late Permian and Triassic temnospondyl amphibians: evidence for a provincialised stereospondyl radiation originating in western Gondwana

Daniel D. Cashmore¹ and Richard J. Butler¹

¹University of Birmingham

Temnospondyls were the most speciose group of extinct amphibians. In the late Palaeozoic-early Mesozoic they inhabited the supercontinent of Pangaea during the unique environmental and biotic conditions of the end-Permian mass extinction and the subsequent Triassic recovery. They have an abundant fossil record and their worldwide distribution makes them ideal for biogeographical analysis. Geographical and phylogenetic data was collected for 143 late Permian-Triassic temnospondyls and a time-slicing protocol was implemented. By combining the most recent temnospondyl phylogenies each species was incorporated into a new informal supertree, to which a number of biogeographical methods were applied, including event-based tree-fitting, tests of palaeolatitudinal consistency and ancestral area reconstruction analyses. Results suggest that late Permian and Early Triassic temnospondyl faunas were latitudinally provincialised as a result of climatic variation, with biogeographical processes governed by within-area speciation and minimal dispersal. By contrast, the Middle Triassic temnospondyl fauna was cosmopolitan and apparently unrestricted by any climatic or geographical barriers, whereas the Late Triassic had a latitudinally provincialised fauna governed by within-area speciation, again likely due to climatic controls. Ancestral area reconstructions also suggest that Stereospondyli originated within the late Permian of western Gondwana.

Phylogeny of glypheidean lobsters (Crustacea, Decapoda)

Sylvain Charbonnier¹, ^*Denis Audo² and Véronique Barriel¹

¹UMR 7207 (CR2P) MNHN/UPMC, Département Histoire de la Terre, Muséum national d’Histoire naturelle, Paris, France
²Université de Rennes 1, EA 7316 'Biodiversité et Gestion des Territoires'

Glypheidean lobsters form a particularly specialized group of decapod crustaceans, which are highly diversified in the fossil record. They appeared in the Triassic, prospered in the Jurassic, and subsequently declined between the Cretaceous and the Eocene. They were thought to have become extinct in the Eocene until the discovery of 2 extant species from the Pacific. These discoveries raised questions about the phylogenetic position traditionally assigned to the glypheideans. If their position within Reptantia is still under debate, the delimitation of the whole group and the relationships with its close relatives are even more controversial. We present a phylogenetic analysis of 31 species: 27 fossil species from 7 families (Glypheidae, Litogastridae, Mecochiridae, Pemphicidae, Erymidae, Clytiopsidae, Chimaerastacidae), and 4 extant species from 3 families (Glypheidae, Nephropidae, Stenopodidae). Most of the genera are coded exclusively based upon their type species and, as much as possible, based upon the type specimens. The cladistic analysis demonstrates that glypheideans form a monophyletic group including 2 superfamilies (Glypheoidea, Pemphicoidea). Glypheoidea includes 3 families (Glypheidae, Mecochiridae, Litogastridae). Litogastridae is the sister-group of the clade Glypheidae+Mecochiridae. Pemphicoidea includes a single family: Pemphicidae. A new classification is proposed and currently known genera are rearranged based upon the phylogenetic analysis.

A new Courceyan (Lower Carboniferous) eumalacostracan crustacean from the Forest of Dean.

Neil DL Clark¹, Rollo Gillespie² and Sam F Morris³

¹The Hunterian, Glasgow
²Kempsey, Worcestershire
³NHM, London

In 1982 the carapaces of an unknown Carboniferous crustacean were  presented to the Natural History Museum. It was originally thought that these may represent a new species of Tealliocaris. Further, better preserved, material has since been collected from the Great Doward in the Forest of Dean which allows a better comparison with other Carboniferous crustaceans. The new crustacean shows similarities with Tealliocaris and the Scottish and Northern English crustacean Pseudogalathea. Although there are similarities, there are also some significant differences in the shape of the carapace and the ornamentation of the carapace and pleon. The broad, squat telson is more akin to Pseudogalathea, but the length of the pleon and the lack of elongated sharp postero-lateral angles to the carapace  is more like that of Tealliocaris. The lack of a scaphocerite and the lack of an enlarged third pleomere is more suggestive of affinities with Pseudogalathea however. PCA on 12 landmarks of the carapace indicate that this new crustacean is quite distinct from both Tealliocaris and Pseudogalathea and represents a new genus and species of Lower Carboniferous eumalacostracan. Comparisons with other fossil crustaceans from around the world also suggest that this new crustacean is morphologically similar to Chaocaris, Tylocaris, Fujianocaris, Pseudogalathea and Tealliocaris.

To what extent does depositional environment affect particle morphology in charcoal assemblages?

^*Alastair J. Crawford¹ and Claire M. Belcher¹

¹University of Exeter

Charcoal particles, produced in wildfires and preserved in sediments, are a valuable indicator of past fire activity and environmental change.  One source of this information is their morphology, which can indicate the botanical affinity of the source material, and may also affect the suitability of different methods for measuring charcoal quantity.

Previous work on this subject has focused on Late Quaternary lake sediments, which often present an optimal environment for preservation of the charcoal record.  However other sedimentary archives may be studied, which may relate to different timescales and different taphonomic processes, and lead to differently preserved morphologies.

We have extracted mesocharcoal particles (> 125 µm) from a Mid-Late Holocene peat core, and from Mesozoic sedimentary rocks, and used image analysis to characterise the morphological variation in the charcoal present in these samples.

We will consider the effects of depositional environment and age on morphology, and whether these result in differential preservation of morphological information.  We will assess whether such differences have implications for the quantification of charcoal particles, and thus for reconstructions of levels of fire activity, and whether they may affect the potential for broad taxonomic identification.

Testing habitat transitions in the first supertree of true crabs and hermit crabs (Brachyura and Anomura).

^*Katie E. Davis¹, Tim Astrop¹ and Matthew A. Wills¹

¹University of Bath

It is generally accepted now from both morphological and molecular data that the infra-orders Anomura (hermit crabs & squat lobsters) and Brachyura (true crabs) are sister taxa, making up the clade Meiura. Relationships within these clades are however less clear. There is a wealth of phylogenetic data available for both groups therefore supertree approaches lend themselves well to reconstructing a species-level phylogeny.   Crabs are generally regarded as ocean-dwellers and although the vast majority of brachyurans are marine, there are 850 tropical and subtropical species living in freshwater, semi-terrestrial or terrestrial habitats. Similarly anomurans also occupy semi-terrestrial, freshwater and marine habitats. Historically, it was assumed that the transition from marine environments occurred just once, but there is growing evidence that within Brachyura there are two (Old and New World) or possibly more freshwater/terrestrial clades.   We have built supertrees for the Brachyura and Anomura with a combined total of 2000 taxa. We have used fossil data to calibrate our supertrees and have collated habitat data from TraitBank to optimise onto our supertrees. Our aim is to test how major events such as the Mesozoic Marine Revolution and the Cretaceous-Tertiary mass extinction affected habitat use and species diversification in these organisms.

Evidence for environmental change driving microevolution in Miocene sticklebacks (Gasterosteus doryssus)

^*Rowan LS Dejardin¹, Melanie J Leng^2,3, Sarah E Metcalfe⁴, Michael A Bell⁵ and Mark A Purnell¹

¹Department of Geology, University of Leicester, Leicester, UK
²NERC Isotope Geosciences Facilities, British Geological Survey, Nottingham, UK
³Centre for Environmental Geochemistry, University of Nottingham, Nottingham, UK
⁴School of Geography, University of Nottingham, Nottingham, UK
⁵Department of Ecology and Evolution, Stony Brook University, New York, USA

Exceptionally preserved three-spine sticklebacks (Gasterosteus doryssus) from the Miocene diatomite of the Truckee Formation of Nevada, USA, provide a rare fossil example of finely resolved, directional microevolution through an interval of ~20 ka. The stickleback themselves have been subject to extensive study, but little has been done to investigate whether microevolutionary change correlates in any way with palaeoenvironmental changes in the lake where they lived. Here we test this hypothesis using microfossil data (diatom assemblages) and isotopic composition (δ¹³C_bulk, δ¹³C_diatom, and δ¹⁸O_diatom) as proxies for environmental and climatic change. Our analysis reveals that these proxies record a palaeoenvironmental trend towards increased evaporation, causing decreased lake-level and increased productivity, a trend that correlates with evolutionary changes in stickleback morphology. The hypothesis that this reflects a causal relationship is difficult to test, but a reduction in lake-level potentially drove stickleback microevolution by shifting predation pressures linked to increasingly benthic habitats in a shallower lake. Such adaptive morphological responses to changes in predation pressure are well documented in extant stickleback but this may be the first evidence for comparable adaptive responses in the fossil record.

The associated remains of a lamniform shark from the Maastrichtian (late Cretaceous) phosphates of northern Morocco.

^*Neil Donnelly¹, Charlie J Underwood¹, David J Ward² and Emma L Bernard²

¹School of Earth Sciences, Birkbeck College, Malet Street, London WC1E 7HX, UK
²Department of Earth Sciences, The Natural History Museum, London SW7 5BD, UK

The extinct lamniform shark "Cretalamna" maroccana, (Arambourg) is thought to have lived in the period between the late Cretaceous (Maastrichtian) and the Early Paleocene (Danian). Whilst relatively common in the fossil record, "C". maroccana has previously only been described from isolated teeth and is consequently poorly understood. In February 2014 representatives from the Department of Earth Sciences at the Natural History Museum (NHMUK), London, purchased a plaster-jacketed block of poorly consolidated phosphorite from a commercial dealer at Ouled Bouali, Morocco. This block contains an exceptionally preserved specimen of "C". maroccana comprising 69 teeth, 59 associated vertebra, jaw and skull material. Additionally present are 29 vertebra in separate blocks.

Our work focuses on tooth morphology, dentition reconstruction and description of vertebra. Sampling microvertebrate fauna in the phosphorite matrix helped confirm the specimen’s stratigraphic provenance, stated as and consistent with the vertebrate bone bed 2.65m below the top of the Maastrichtian sediments at Sidi Chennane phosphate pit.

The genus Cretalamna is currently used to accommodate a number of species that share few features with the type species, Cretalamna appendiculata (Agassiz) and should be considered generically distinct. Reconstructing the dentition of "C". maroccana is essential in determining its phylogenetic relationships within the lamniformes.

New crinoids from the Lynton Formation (Devonian) of the Valley of Rocks, north Devon, England

^*S.K. Donovan¹ and F.E. Fearnhead²

¹Department of Geology, Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, Netherlands
²The Natural History Museum, Cromwell Road, London, SW7 5BD, UK

Studies of British Devonian crinoid columnals have lagged behind those of the Lower Palaeozoic and Mississippian, yet museum collections are replete with unidentified material. F.E.F. undertook a short field season collecting from the Lower-Middle Devonian of the Valley of Rocks, west of Lynton, north Devon. Specimens were collected from (mainly) the Lynton Slates Formation (Emsian to Eifelian; Lower to Upper Devonian). This site preserves rich columnal accumulations. The Lower Devonian crinoids of south-west England remain poorly known, while those of the Middle Devonian are known mainly from the Givetian limestones of south Devon.

Columnals (rarely pluricolumnals and brachials) are preserved as external moulds on slabs of fine-grained sandstone that are conducive to casting in rubber. Diversity is limited, perhaps six or so morphospecies. Some taxa are reminiscent of those described by Le Menn from coeval rocks of Portugal and the Boulonnais, northern France. The commonest columnals are from the proxistele of the monobathrid Hexacrinites. We conclude that studies of British Devonian crinoid columnals have the potential to provide data and insights that are not possible from the rarer thecal material found at relatively few sites.

F.E.F. acknowledges the support of an award from the Richard Owen Research Fund, Palaeontographical Society.

Quantifying diffusion periods in marine and terrestrial vertebrate fossils using rare earth elements

^*Amanda E Drewicz¹, David E Grandstaff², Dennis O Terry² and Richard D Ash³

¹Boise State University
²Temple University
³University of Maryland

Rare earth elements (REE), trace elements (TE), and uranium (U) in vertebrate fossils have been used to study taphonomy/reworking, stratigraphic correlation, paleodiet, fossilization processes, and as proxies for paleoenvironment reconstruction. REE and U are incorporated in fossils by diffusion during apatite recrystallization. Recrystallization periods in bone are poorly known, but may be calculated using diffusion models. This allows better refinement of temporal resolution of geochemically based paleoenvironmental reconstructions. Five late Eocene brontothere bones from the White River Group and three Miocene marine mammals from the U.S. Atlantic Coastal Plain were analyzed using LA-ICP-MS. Compared to terrestrial fossils, REE depth fractionation is less pronounced in marine specimens, which may result from a greater influence of secondary diffusion pathways (Haversian systems). Diffusion periods were shorter in marine fossils (0.9 to 2.8 ka), when compared to terrestrial specimens (2.2 to 55 ka). Discrepancies in diffusion periods may result from intermittent aqueous saturation in terrestrial environments. Previous studies of soft tissue preservation in fossil bone concluded that diffusion must outpace decay for soft tissue preservation. The calculated diffusion periods suggest that biomolecule preservation in deep time would be favored in water-saturated environments.

Analysing dinosaur biogeographic connectivity in relation to Mesozoic continental fragmentation

^*Alexander M. Dunhill¹ and James Sciberras²

¹University of Leeds
²University of Bath

Network Theory is widely used in a number of diverse fields and is a powerful framework for studying the structure of biological systems. Despite this, it has been seldom used in palaeobiological studies. Here, we use network analysis to map dinosaur connectivity across major continental landmasses through time. We also present a second set of network models illustrating Mesozoic continental fragmentation. Results show that family-level connectivity increases through the Mesozoic, despite the ongoing fragmentation of major continental landmasses and rising sea levels. However, the establishment of novel connections decrease through time and are thus positively correlated with continental connectivity. These results shows that, as major landmasses underwent fragmentation from Pangaea, to Laurasia and Gondwana, through to complete separation, the potential for novel interconnectivity between continental dinosaur communities decreased significantly. This suggests that the higher taxonomic structure of dinosaur biogeography was established earlier in the Mesozoic, when all landmasses were linked via continental aggregation or sea level-driven land bridge formation. This biogeographic pattern was then sustained through to the end of the Cretaceous.

Taphonomic biases in Quaternary reef corals of Indonesia

^*Kilian KE Eichenseer¹ and Wolfgang WK Kiessling¹

¹Friedrich-Alexander-Universität Erlangen-Nürnberg

Information from fossil coral reefs is increasingly used to explore the sensitivity of these ecosystems to climate change. However, a fossil reef does not represent a perfect image of the former living reef. To determine the magnitude and causes of the expected bias by taphonomic processes, we analysed living and fossil coral reefs on Sulawesi (Indonesia). We quantified the coral fauna focussing on the three dominant families (Acroporidae, Faviidae and Poritidae) and compared their relative abundance today and in three Quaternary reef terraces. These range in age from the Holocene to the Last Interglacial ca. 130 ky ago. Multiple locations were studied and ANOVA applied to separate temporal from spatial variability. All but one fossil reef are depleted in poritids and enriched in faviids relative to today, but only the depletion in poritids is likely a true taphonomic bias. Even though the fossil record of Quaternary coral faunas does not exactly mirror the former taxonomic live composition, the bias is small enough that biological signals, which may arise from climate change, can be recognized.

Palaeoecology of Cenozoic marine molluscs using stable isotopes of shell-bound organic matter (SBOM)

^*Hannah C. Elms¹, Edine Pape¹, Martin Zushchin², Fiona L. Gill¹, Crispin T. S. Little¹ and Robert J. Newton¹

¹University of Leeds
²University of Vienna

Reconstructions of feeding strategies of fossils are usually based on analogy using the diet of modern relatives, where available.  However, direct evidence for such fossil feeding strategies is currently limited. Carbon, nitrogen and sulfur stable isotopic signatures in shell bound organic matter (SBOM) of molluscs are related to those of soft tissues, which are affected by diet. This project investigates the SBOM stable isotope signature of Miocene marine  molluscs interpreted to have three distinct feeding strategies. If there is a consistent relationship between feeding strategy and isotopic signature, this approach has the potential to aid understanding of the diet of fossil marine fauna and trophic structure of past marine ecosystems.

 SBOM was extracted from six Miocene gastropod species and one modern species, spanning a range of assumed feeding strategies including carnivory, algal detrital grazing and filter feeding.  Inter-crystalline and intra-crystalline SBOM were analysed separately, as intra-crystalline SBOM is thought to be less susceptible to diagenetic alteration.

We present isotopic data as evidence for diverse feeding strategies in Cenozoic marine fossils. This approach has previously been used to investigate chemosymbiosis in the fossil record. Here it is extended to evaluate the SBOM isotopic signatures for a wider range of nutritional strategies.

Reconstructing ancestral animal feeding modes; a Bayesian inference on the origin of predation.

^*Cesar A Espinoza-Campuzano¹, Jakob Vinther¹, Davide Pisani¹ and Erik Sperling²

¹School of Earth Sciences and Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
²Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge MA 02138

The evolution of predation is an important transition in animal evolution. The appearance of macrophagous carnivores may have spurred the Cambrian explosion. While several carnivorous groups appear in the early Cambrian, the true origin might be more ancient. It is not clear if predation evolved convergently in several lineages or if it is ancestral to several phyla and the timing of this evolution is key claiming causality for the Cambrian explosion.

To test these linkages, we implemented an ancestral character reconstruction (ACR) using a time-calibrated phylogenetic tree of over 223 metazoan taxa. According to the best model for our database and with phylogenetic uncertainty taken into account, the first ancestor that is strongly supported as a predator was the node of Nemertea in the late Ediacaran (556 My).

This date supports an arms-race driver for the Cambrian explosion. However, in some analyses several deeper nodes were reconstructed as predators, albeit with low Bayesian support. In particular the ancestors of Ecdysozoa and Protostomia (Ediacaran and late Cryogenian, respectively); which would decouple the origins of predation from the Cambrian radiation. We further present a novel geochemical ACR that gives similar predator nodes as the qualitative one:  Ecdysozoa or Nemertea + Platyhelminthes.

The Identification & Advisory Service Natural History Museum, UK

^*F.E Fearnhead¹, S Hine¹, F Feneru¹, C Fisher¹ and F. Rumsey¹

¹The Natural History Museum, London. UK

Natural History has been a popular pastime in the British Isles for over 200 years. That it retains its popularity is undoubtedly due to multiple influences, such as by David Attenborough’s enthusiasm in authored documentaries such as Life on Earth, Blue Planet and Natural Curiosities. This curiosity has resulted in many people asking ‘What is this?’ and directing their queries to the Angela Marmont Centre at the Natural History Museum (NHM), where we try to provide informed answers. With the great interconnectivity provided by the www, Facebook, Twitter, etc., scientific knowledge has become accessible to a far wider public audience. Emerging media technologies service on a wide range of digital platforms and devices have enabled boundaries to be crossed, supporting equality of opportunity. All these innovations have impacted on the Identification and Advisory Service of the NHM and have contributed to changes in the type of questions asked and the style of enquiries. The challenge for the Identification and Advisory Service is how to support an ever increasing number of enquiries, providing authentic answers to more sophisticated questions, supporting enquirer learning towards a better understanding and knowledge of taxonomy.

Test abnormalities in larger benthic foraminifera from hypersaline coastal ponds of the United Arab Emirates (UAE)

Flavia Fiorini¹ and Stephen W. Lokier¹

¹The Petroleum Institute, P.O. Box 2533, Abu Dhabi, United Arab Emirates

The benthic foraminifera assemblage from Recent coastal ponds located in the intertidal zone of the UAE Western Region was investigated with the aim of providing modern analogs for understanding ancient near-shore environments.

The studied hypersaline coastal ponds are located between a lagoonal area and the supratidal sabkha. Detached blades of sea grass and microbial mats were present in the ponds.

The samples show an assemblage dominated by epiphytic larger benthic foraminifera as Peneroplis pertusus and P. planatus. High percentages (up to 50% of the living assemblage) of anomalous tests of the benthic foraminifera Peneroplis, Spirolina and Sorites were observed. The observed anomalies included dissolution, microboring and abnormality in growth. Different forms of abnormal test architecture were recorded: presence of multiple apertures with reduced size, deformation in the test shape and abnormal coiling.

The high percentage of abnormal tests reflects natural environmental stress. The unique presence of epiphytic species, suggests that they may be transported into the pond together with seagrass either during high-tides or storm surge events, and continued to live in the pond. This hypothesis is supported by the fact that all the abnormal foraminifera are adult and show a normal proloculus and normal growth of the earlier chambers.

The Anthropopcene Biostratigraphy of Leicestershire

^*Deborah Fish¹

¹University of Leicester

The Anthropocene reflects a large biological impact as a result of human interaction with the environment. Leicestershire, England shows evidence of this impact from the beginning of the Holocene to present day, using archaeological findings and more traditional geological techniques, such as core logging in lakes. The impact is most clearly seen in mammals, due to their uses as food sources and pets. Changes in mammal composition in the region have not been constant over the Holocene, and a wave of introductions and extinctions came with each human invasion of the UK. The most obvious change is within the past 1000 years, as human population of the area exploded, with the spread of urban areas and the expansion of global trade. Other types of fauna analysed, specifically gastropods and ostracods, react to human influence differently to mammals, as they are not directly used for human benefit. These invertebrates likely respond more closely to changes in forest cover and temperature. The successive assemblages reflect human impact on the biology of Leicestershire, and may help constrain boundary level between the Anthropocene and the Holocene.

The microorganisms of a 430-million-year-old hydrothermal vent community

^*Magdalena N. Georgieva^1,2, Crispin T.S. Little¹, Adrian G. Glover² and Alexander D. Ball²

¹University of Leeds
²Natural History Museum

Microorganisms are the chief primary producers within present-day deep-sea hydrothermal vent ecosystems, and play a fundamental role in shaping the ecology of these unique environments. However, little is known about the microorganisms that occurred within, and structured ancient vent communities - their evolutionary history, diversity, and the nature of their interactions with hydrothermal vent animals are largely undetermined. The oldest known hydrothermal vent community occurs within the Yaman-Kasy deposit of the Ural mountains, Russia, which dates back to the Silurian, 430 MYA. This deposit contains two types of dwelling tube fossils attributed to the polychaete worms – the large tubes of Yamankasia rifeia, and the smaller tubes of Eoalvinelloides annulatus. A re-examination of these tube fossils using scanning electron microscopy reveals the preservation of several filament morphotypes that strongly resemble modern hydrothermal vent microbial filaments, such as those preserved within the mineralised tubes of the vent polychaete genus Alvinella. At least three distinct filament types showing different spatial distributions are found in association with the Yaman-Kasy fossil tubes. These results represent the oldest animal-microbial associations preserved within an ancient hydrothermal vent environment, and shed insights into the diversity of microorganisms within ancient vents, and into the palaeoecology of these systems.

Synchrotron ultraviolet luminescence microscopy and spectroscopy of well-preserved fossils: preliminary results

^*Pierre Gueriau^1,2, Mathieu Thoury^2,3, Tatiana Séverin-Fabiani^2,3, Matthieu Réfrégiers³, Didier B. Dutheil¹, Bouziane Khalloufi¹ and Loïc Bertrand^2,3

¹Muséum national d’Histoire naturelle, CR2P, UMR 7207 CNRS, MNHN, UPMC, 57 rue Cuvier, CP 38, F-75005, Paris, France
²IPANEMA, CNRS, MCC, USR 3461, BP48 Saint-Aubin, F-91192 Gif-sur-Yvette, France
³SOLEIL synchrotron, BP48 Saint-Aubin, F-91192 Gif-sur-Yvette, France

Ultraviolet (UV) photography is now used on a regular basis in palaeontology, as it allows showing hidden bony sutures, and to separate bones, scales or soft parts from the underlying matrix or each other. However, we know almost nothing of the chemical basis behind the structures that can be seen in fossils using UV. Nevertheless, most of these different fossilized tissues – both mineralized skeleton bioapatite and authigenic apatite that have replicated soft-tissues such as muscles, are mineralized in apatite group minerals, which are among the most interesting luminescent minerals, this luminescence being often associated with the incorporation of rare earth elements. We used synchrotron UV luminescence microscopy and spectroscopy at the DISCO beamline (SOLEIL synchrotron, France) on well-preserved fossil fishes and shrimps from the Djebel Oum Tkout Lagerstätte (Late Cretaceous of Morocco) in order to address this issue. Preliminary UV/visible luminescence imaging experiments clearly reveal luminescence distribution patterns and allow highlighting anatomical structures previously indiscernible. On another hand, high spatial resolution UV/visible luminescence emission spectra display emission bands consistent with cerium incorporation in apatite minerals. Such new tools therefore appear very promising for the visualization of indiscernible or hardly discernible anatomical details and to get insight into diagenetic processes.

Records of Antarctic seasonal variation preserved in bivalve shells across the Cretaceous/Paleogene mass extinction.

^*Joanna L.O. Hall¹, Alan M. Haywood¹, Stephen J. Hunter¹, Robert J. Newton¹, Jane E. Francis², J. Alistair Crame² and Elizabeth M. Harper³

¹University of Leeds
²British Antarctic Survey
³University of Cambridge

The Late Cretaceous to Early Paleogene of Antarctica has long been highlighted as a time of extreme seasonality on a scale unseen in modern temperate climates.  This potential for heightened seasonal variability is often overlooked in interpretations of geochemical proxy records which may result in misleading paleoenvironment reconstructions. 

Seymour Island’s many species of thick-shelled bivalves serve as valuable high resolution multiproxy archives in the marine realm.  Microanalysis of well-preserved original shell carbonate can be used to provide near-monthly paleoenvironmental data including proxies for temperature, water geochemistry and productivity during annual growing seasons.

Long-lived bivalves of the genus Lahillia and Cucullaea, found in the pre-extinction and recovery fauna across the Cretaceous-Paleogene boundary sequence have been examined to assess preservation for use as archives of seasonal climate information.  High resolution stable isotope results show trends related to visible annual growth banding in the valve and tooth which allow reconstruction of age and growth history of individual specimens.  Here we present the results of preservation studies and initial high resolution geochemical analyses and discuss subsequent potential for reconstruction of seasonal trends through the stratigraphic sequence on Seymour Island to yield new paleoecology data.

Packed with shells: unusual burrows in the Oligocene of Antigua, West Indies

David A.T. Harper¹, Stephen K. Donovan² and Roger W. Portell³

¹Durham University
²Naturalis Biodiversity Center, Leiden
³Florida Museum of Natural History

Ichnology is a Cinderella area of study in Antillean Earth Sciences, with rare, well-studied exceptions such as the Cenozoic of Jamaica and the Middle Miocene of Carriacou. The authors are currently correcting this omission on one island, Antigua, principally in the Upper Oligocene Antigua Formation. Although identifiable traces include ichnogenera already well known from the region, rare burrows at two sites are unusual, being filled with densely packed debris of the shelly benthos. Unlined burrows (Planolites) in deep-water biofacies at Half Moon Bay, parish of Saint Philip, are packed with a monospecific assemblage of large benthic foraminiferans (Lepidocyclina canelli Lemoine & Douvillé) and a single brachiopod valve, Tichosina sp. A similar burrow in shallower-water biofacies at Hughes Point, parish of Saint Philip, is packed with asteroid marginal ossicles and, particularly, test fragments of the spatangoid echinoid Lovenia n. sp. Fragments of the same echinoid line the burrow attributed to sea anemones, Bergaueria isp. The latter is probably a physical accumulation, the common fragments of echinoid being washed into an empty burrow. In contrast, the infill of Planolites isp. is more likely to be an accumulation mediated by the burrower.

We gratefully acknowledge support provided by National Geographic Society grant #GEFNE55-12.

Palaeoecological analysis of a highly diverse Late Triassic marine biota from the Cassian Formation (North Italy, Dolomites)

^*Imelda M. Hausmann¹ and Alexander Nützel²

¹Department für Paläontologie, Universität Wien, 1090 Vienna, Austria; imelda.hausmann@gmx.de
²SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, Department für Geo- und Umweltwissenschaften, Paläontologie & Geobiologie, Geobio-Centre, Ludwig- Maximilians-Universität München, 80333 Munich, Germany; a.nuetzel@lrz.uni-muenchen.de

A bulk sample of marine invertebrates from the Late Triassic Cassian Formation (North Italy, Dolomites) yields one of the most diverse Early Mesozoic fossil assemblages ever reported. The assemblage is strongly dominated by molluscs, especially by gastropods. Rarefaction analyses suggest that the bulk sample and a surface collection from the same locality share the same diversity. However, taxonomic composition, species richness and rank abundance differ strongly according to sampling method. Most of the fossils are smaller than 1 cm reflecting small adult sizes and size sorting during transport. Fragmentation, microbial encrustation and the high portion of ooids, oncoids and peloids indicate that the fossil assemblage was transported from a carbonate platform into the adjacent basin, where it was embedded within basin clays. The low-grade lithification of clayey sediments facilitates the disaggregation, the discovering of small fossils, and hence the recognition of this especially high diversity. Sample standardization shows that the studied Late Triassic assemblage is much more diverse than other Early Triassic marine assemblages, but diversity is comparable to Anisian (Middle Triassic) assemblages. According to current models, the diversity of the studied marine assemblage meets the predictions for the transition from the niche overlap to the habitat contraction phase.

The Llanfalteg biota – exceptional preservation of a Burgess Shale-type arthropod from the Middle Ordovician of south Wales

^*Thomas W Hearing^1,2, David A Legg³ and Martin D Brasier^1,3

¹Department of Earth Science, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK
²Department of Geology, University of Leicester
,
 University Road
, Leicester
, LE1 7RH, UK
³Oxford University Museum of Natural History, Parks Road, Oxford, OX1 3PW, UK

Soft-bodied invertebrates are well-known from Cambrian konservat-lagerstätten but are thought to disappear by the end of this period, replaced by a ‘lsquo;Palaeozoic evolutionary fauna’ dominated by suspension feeding brachiopods, echinoderms, and cephalopods. Two principle hypotheses have been invoked to explain this disappearance: (a) a real and immediate biotic turnover, and (b) changing seafloor taphonomic conditions, possibly related to increasing bioturbation. Although recent discoveries of post-Cambrian Burgess Shale-type (BST) konservat-lagerstätten challenge the first hypothesis, available examples have been stratigraphically sporadic (Lower Ordovican Fezouata Formation, Morocco; Upper Ordovician Soom Shale, South Africa) and provide only isolated snap-shots of ancient biodiversity. A newly discovered xenopod arthropod, Etainia howellsorum, from the Middle Ordovician Llanfalteg Formation, south Wales, plus associated fossils, help to bridge the gap. This taxon shows similarities to Emeraldella and Sidneyia from the middle Cambrian Burgess Shale Formation. In the Llanfalteg Formation, this BST taxon coexisted with benthic taxa more typical for the Middle Ordovician of Avalonia, including atheloptic trilobites, some with phosphatised digestive tracts. This site extends the stratigraphic ranges of an otherwise exclusively Cambrian clade, and throws a new light upon the taphonomic pathways required to preserve such animals.

Fossil ostracods as proxies for salinity changes on the south-western shelf of the Black Sea during the Holocene

David J. Horne¹, Lee Bradley² and Lorna Williams³

¹Queen Mary University of London, UK
²University of Liverpool, UK
³Fugro Geosurveys, St John's, Canada

The Holocene reconnection of the Black Sea to the Mediterranean has provoked debate on several issues including Black Sea salinity prior to the establishment of the present two-way flow through the Bosphorus Strait. Fossil ostracod analyses in sediment cores from the south-western shelf of the Black Sea facilitate a qualitative reconstruction of past salinity levels.  Ostracod preservation is good throughout and often excellent, with occasional soft-part preservation. Taphonomic analyses show that most of the significant taxa are in situ (with suites of adult and juvenile moult stages) and show little evidence of post-mortem transport, mixing or size-sorting.  Before the reconnection, “caspi-brackish” assemblages including Amnicythere olivia (Livental, 1938), Amnicythere quinquetuberculata (Schweyer, 1949), Candona schweyeri Schornikov, 1964, Euxinocythere bacuana (Livental, 1929) and Loxoconcha lepida Stepanaitys, 1962 are present, indicative of low-salinity brackish water. There is no evidence for freshwater as has been claimed by some authors; indeed there is marked absence of typical freshwater ostracods such as are common in surrounding areas today as well as in the Holocene.  After reconnection, assemblages typically include marine species with Mediterranean affinities such as Carinocythereis carinata (Roemer, 1838), Cytheroma marinovi Schornikov, 1967, Hiltermannicythere rubra pontica (Dubowksi, 1939) and Palmoconcha agilis (Ruggieri, 1967).

Reconstructing the rangeomorph body plan: fractal models reveal adaptive optimisation in the Ediacaran

^*Jennifer Hoyal Cuthill¹ and Simon Conway Morris¹

¹Department of Earth Sciences, University of Cambridge

The large, frond-like “rangeomorphs”, which make a dramatic entrance into the fossil record during the late Ediacaran Period (from 580 Ma), have been called bizarre, fractal and a failed experiment in evolution. As some of the earliest known macro-organisms they offer tantalising insights into the evolution of multicellular eukaryotes. However, rangeomorphs are morphologically distinctive and inhabited the non-uniformitarian Precambrian oceans. As a result, many questions regarding their patterns of growth and development, the validity of the rangeomorph clade, their feeding mode, adaptive optimality, and ultimate extinction have proved difficult to answer. Here, we present a unified quantitative model for rangeomorph growth, development and resultant morphology, using parametric Lindenmayer systems. This provides a formal description of their fractal branching patterns and supports a rangeomorph clade united by a shared body plan. By reproducing rangeomorph branching patterns, we generate realistic 3D computer models which allow us to estimate functionally relevant properties of their morphologies. This sheds new light on their feeding mode and efficiency as well as the reasons for their disappearance around the Cambrian boundary.

New occurrences and extension of the stratigraphical range of discoidal Ediacara-type fossils on the Digermul Peninsula, northern Norway

Anette E.S. Högstrom¹, Jan-Ove Ebbestad², Sören Jensen³, Teodoro Palacios³, Guido Meinhold⁴, Wendy L. Taylor⁵, Linn K. Novis¹, Heda Agic⁶ and Małgorzata Moczydłowska⁶

¹Tromsø University Museum, Natural Sciences
²Museum of Evolution, Uppsala University
³Universidad de Extremadura, Badajoz
⁴Geoscience Center of the University of Göttingen
⁵Department of Geological Sciences, University of Cape Town
⁶Department of Earth Sciences, Uppsala University

In Scandinavia the evolutionary events across the Ediacaran‒Cambrian transition can only be studied in continuous section on the Digermul Peninsula, northern Norway, in the siliciclastic Stáhpogiedde Formation. This roughly 500-m-thick unit comprises, in ascending order, the Lillevannet, Innerelva and Manndraperelva members. Trace fossils, including Treptichnus pedum, and organic-walled microfossils, including Granomarginata prima, position the base of the Cambrian in the upper part of the Manndraperelva Mbr. Some 20 years ago discoidal Ediacara-type fossils were found in the middle part of Innerelva Mbr. Recent field seasons have provided abundant new material of Aspidella-type fossils and extended their stratigraphical range to within about 15 meters above the Lillevannet Member. The exclusive presence of discoidal forms may reflect a taphonomic bias and/or be evidence of a greater age than that of the more diverse Ediacaran assemblages. That the latter may be the case is indicated by the stratigraphic proximity of the lowest occurrences of Aspidella to the Mortensnes diamictite, recently tentatively considered a Gaskiers glaciation equivalent (ca 580 Ma). This raises the question of hitherto unrecognised breaks in sedimentation in the Stáhpogiedde Formation. In order to explore this question we have sampled the succession for organic-walled microfossils, detrital mineral geochronology and sediment geochemistry.

A new proxy for fossil sunshine based on pollen wall chemistry

^*Phillip E. Jardine¹, Wesley T. Fraser², Barry H. Lomax³ and William D. Gosling⁴

¹The Open University
²Oxford Brookes University
³University of Nottingham
⁴University of Amsterdam

Despite the importance of solar irradiance as a dominant control on Earth’s energy budget, no proxy has been developed that can provide total solar irradiance (TSI) reconstructions prior to the Holocene. Here, we present a novel proxy based on the chemical composition of sporopollenin, the primary component of the outer walls of pollen and spores (sporomorphs). Sporopollenin chemistry is responsive to levels of ultraviolet-B (UV-B) radiation exposure, which offers the possibility of using fossil sporomorph chemistry as a proxy for past UV-B flux and, by extension, TSI. The high preservation potential of sporomorphs means that this new proxy has the potential to reconstruct UV-B and TSI flux over much longer timescales than has previously been possible. Furthermore, Fourier Transform infrared (FTIR) spectroscopy allows sporopollenin chemistry to be rapidly assessed on small sample sizes (≤10 sporomorphs/sample). We demonstrate the utility of this proxy using grass pollen chemistry data from the late Pleistocene of Ghana, and relate this to modelled mean annual TSI. This proxy provides a new approach for quantifying the relationship between TSI, climate and vegetation change. The unpicking of this information offers the tantalising potential to determine how changes in solar irradiance have driven long-term changes in floral assemblages.

Sequence stratigraphic control over biofacies distribution and ecological gradients in the Mississippian Lodgepole Formation, Montana

^*Emilia Jarochowska¹, Allison L. Keller², Julien Kimmig³, Ekaterina Larina⁴, Rhiannon J. LaVine⁵, Katharine M. Loughney⁶, Emily A. Orzechowski⁷, Nadia D. Pierrehumbert⁵, Alexis Rojas⁸, Judith A. Sclafani⁹, Amy Singer¹⁰, Joyce A. Yager¹¹, Max Christie⁹, Sharon K. McMullen¹², Steven M. Holland¹³ and Mark E. Patzkowsky⁹

¹GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
²Department of Earth Sciences, University of California, Riverside, CA, USA
³Department of Geological Sciences, University of Saskatchewan, Saskatoon, Canada
⁴Earth and Environmental Sciences, Brooklyn College, Brooklyn, NY, USA
⁵Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA
⁶Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
⁷Department of Integrative Biology, The University of California, Berkeley, CA, USA
⁸Florida Museum of Natural History, Gainesville, FL, USA
⁹Department of Geosciences, The Pennsylvania State University, University Park, PA, USA
¹⁰Geosciences, University of Montana, Missoula, MT, USA
¹¹Earth Sciences, University of Southern California, Los Angeles, CA, USA
¹²Department of Geosciences, University of Wisconsin-Madison, Madison, WI, USA
¹³Department of Geology, University of Georgia, Athens, GA, USA

Sequence stratigraphy provides the tools to predict the occurrences of marine taxa and test hypotheses on the diversity of faunal assemblages in response to relative sea-level change. We examined this relationship during the Stratigraphic Paleobiology field course sponsored by the Paleontological Society in July 2014.

The Mississippian Lodgepole Fm is represented by three depositional sequences developed in a sub-tropical carbonate platform. We counted over 3000 faunal specimens in 93 field counts within the sequence stratigraphic architecture. Using detrended correspondence analysis (DCA), we have identified two faunal gradients. The first gradient corresponds to water depth, and the second separates taxa by attachment, which we interpret as substrate affinity. DCA reveals no directional change in the position along the onshore-offshore gradient within bedsets representing the same lithofacies across consecutive parasequences, but the influence of the sequence-stratigraphic architecture is visible in the faunal composition at the level of systems tracts. Richness and evenness of samples are both greater in the deep subtidal than in shallower facies. Niche response curves show that more taxa had their preferred environment in deeper-water facies, and that rare taxa have a greater variance in environmental tolerance than common taxa.

In defence of the Fortune Head Cambrian GSSP

Sören Jensen¹ and Graham. E. Budd²

¹Universidad de Extremadura, Badajoz
²Department of Earth Sciences, Uppsala University

The decision to base the Cambrian GSSP on trace fossils was controversial at the time of its ratification in 1994, and has remained so to date. Recently efforts have been set in motion to evaluate if the definition of the base of the Cambrian should be re-opened. We would be more enthusiastic if there were clearly superior globally correlatable levels, but we do not see this being the case. Rather, there are advantages with the current deep placement of the Cambrian GSSP, and we believe its deficiencies have been overstated. It has considerable conceptual value as it undoubtedly approximates a time of biotic radiation and major changes in benthic ecology. It is readily correlatable into most areas, yet so deep that most questions of inter-regional correlation become intra-Cambrian. Claimed problems of correlation into Siberia do not consider a growing body of trace fossil data from northern Siberia. Efforts are certainly needed on advancing knowledge of the Fortune Head GSSP section, including studies to evaluate the sub-GSSP Treptichnus pedum. Work in progress shows that much remains to be done on organic-walled microfossils in this section, and the possibilities to add further chemostratigraphical data should be explored.

Are all characters created equal? Identifying taxonomically meaningful characters in the Ediacaran.

^*Charlotte G Kenchington¹

¹University of Cambridge

The late Neoproterozoic witnessed the emergence of the first complex macro-organisms. Among these are the rangeomorphs, a group of enigmatic forms traditionally grouped with the “Ediacara biota”. Rangeomorphs are pseudo-fractal organisms, including iconic Ediacaran fossils such as Charnia masoni. They have no known close biological relations in the modern world; coupled with their morphological simplicity, this renders rangeomorph taxonomy difficult. This has been the subject of recent debate, with some authors placing weight on branching architecture, and others preferring morphological characters. There is no consensus as to which characters are taxonomically meaningful.  

The historic Ediacaran sites of Charnwood Forest have yielded a plethora of new individuals following a recent casting and moulding project. These include fifty-seven well preserved specimens of Primocandelbrum, which was previously known from only a handful of specimens from Newfoundland. The new specimens show diversity in both morphological and branching characteristics, and can be grouped according to either set of characters, using outgroups of broadly similar but distinct taxa. Comparing the specimen composition of groups defined by each character set identifies those characters that generate the most robust taxonomic groupings. This will constrain our understanding of fundamental aspects of the communities such as species richness and diversity.

Quantitative stratigraphy of Late Devonian and Early Carboniferous ammonoid successions in the Rhenish Mountains (Germany)

^*Carina Klein¹ and Dieter Korn¹

¹Museum fuer Naturkunde Berlin

The application of modern biostratigraphical methods, especially to ammonoid biostratigraphy, helps to clarify the stratigraphical order of the ammonoid occurrences and to minimize contradictions without new extensive sampling efforts being required. We investigated the occurrences of 64 late Famennian (Late Devonian) ammonoid species from 12 sections and 52 early Tournaisian (Early Carboniferous) ammonoid species from 7 sections using three biostratigraphical methods, (1) Unitary Associations (UA), (2) Constrained Optimization (CONOP) and (3) Ranking and Scaling (RASC).

The three methods lead to similar outcomes and the fit with the empirical data is generally good. UA shows the lowest resolution, but leads to the most robust results; CONOP and RASC show a higher resolution. For the Devonian dataset, only the results of the RASC method coincide with the empirical data; the Effenbergia lens, Muessenbiaergia parundulata and Muessenbiaergia sublaevis zones cannot be resolved by the UA and CONOP methods. For the Carboniferous dataset, the results of all methods coincide with the empirical data.

We consider the faster RASC method to be the most suitable; it perfectly coincides with the empirical data. Nonetheless the UA method facilitates the separation of zones and can thus be seen as a useful method, too.

Functional morphology of non-mammalian cynodonts and their kin

^*Stephan Lautenschlager¹, Emily J. Rayfield¹, Pamela Gill¹ and Michael Fagan²

¹School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ
²School of Engineering, University of Hull, Cottingham Road, HU6 7RX Hull

The evolution of mammals is a textbook example for the acquisition of morphological and functional modifications. They are most pronounced in the cranial skeleton, including a differentiated, heterodont dentition and the transformation of the jaw joint, resulting.

Although these osteological modifications are well-documented in the fossil record, the fossil remains of cynodonts are often subject to taphonomic deformation and incompletely preserved. Here we present digital reconstructions of the cranial osteology and myology of different non-mammalian cynodonts, including Thrinaxodon and Probainognathus.

Based on computed tomography (CT) scanning, models of the cranial skeleton of these taxa were digitally restored. Subsequently, the muscle architecture was reconstructed in an iterative approach. The restored osteological models and reconstructed myology were used to perform Multibody Dynamics Analyses to assess muscle and bite forces, as well as Finite Element Analysis to elucidate the biomechanical behaviour.

Results show that the muscle architecture changed between the various taxa. While there are indications for the retention of a pseudotemporalis muscle complex in Thrinaxodon, these muscles appear to be absent in the more derived Probainognathus. However, this transformation of the muscle arrangement has little effect on the resulting bite forces, which are slightly higher in Thrinaxodon.

Reinterpretion of the problematic Ordovician genus Bolboporites (?Echinodermata) as a calcareous alga

Bertrand Lefebvre¹

¹UMR CNRS 5276, bâtiment Géode, Campus de la Doua, Université Lyon 1, 2 rue Raphaël Dubois, F-69622 Villeurbanne cedex, France; bertrand.lefebvre@univ-lyon1.fr

Bolboporites is a relatively small (about 1.5 cm long), cone-shaped fossil, characterized by a typical honey-comb like sculpture on its external walls; a gently domed upper surface with two adjoining U-shaped structures; and an internal, longitudinal axis. This genus is fairly common in the Ordovician (Floian-Katian) of Baltica (Estonia, Russia, Scandinavia). It was also reported from the Upper Ordovician of Laurentia (Canada, USA). Although initially described as a coral, the genus Bolboporites Pander, 1830 was generally considered to represent either a portion of, or the complete body (theca) of an echinoderm of unknown affinities. The Natural History Museum of Oslo contains abundant, exceptionally well-preserved specimens of Bolboporites from the Upper Ordovician of Norway. The careful reexamination of this material does not confirm its interpretation as an echinoderm. On the other hand, striking similarities with the morphology of Ordovician cyclocrinitids (e.g., Coelosphaeridium) rather suggest that Bolboporites more likely represents a calcareous alga.

Testing Life-Habits of Hatchling Ammonites using CT Data

^*Robert RE Lemanis¹, Rene RH Hoffmann¹ and Stefan SZ Zachow²

¹Ruhr Universitaet Bochum
²Zuse Insitute

The reproductive strategy of ammonoids has been considered an important component to their global distribution and survivability through extinction events. High fecundity and small egg sizes (around 1 mm) separate ammonoids from nautiloids who produce a small number of eggs with hatchlings around 2 cm in diameter. Ammonoid hatchlings have been viewed as planktonic, exploiting ocean currents to maximize their geographic distribution. However direct testing of this life-habit through study of the physical properties of the shell has been sparse and quantification of the buoyant and hydrostatic properties of hatchlings has been limited to geometric analysis of hypothetical, ideal shell shapes.  Using exceptionally preserved hollow ammonite fossils and synchrotron microtomography (SRµCT) we present a case study testing the validity of geometric approximations of shell volume using a Jurassic ammonite Cadoceras sp. hatchling. Buoyancy, hydrostatics, and swimming velocity are calculated for a range of shell parameters. Cadoceras exhibits buoyancy values from -0.25µN to 0.36µN. Buoyancy and swimming speeds are similar to extant coleoid hatchlings demonstrating a possible similarity in hydromechanics. Volumetric calculation based on high resolution CT data is the most accurate current method and is also important for the utilization of ammonoid shells as archives for palaeoenvironmetal data.

Rare non-trilobite arthropods from the Weeks Formation Konservat-Lagerstätte (Cambrian, USA)

Rudy Lerosey-Aubril¹, Javier Ortega-Hernández², Carlo Kier³, Enrico Bonino³ and ^*Emmanuel L. O. Martin¹

¹Laboratoire de Géologie de Lyon: Terre, Planètes, Environnement (UMR 5276, CNRS), Université Claude Bernard Lyon 1, Villeurbanne, France
²Department of Earth Sciences, University of Cambridge, Cambridge, UK
³Back to the Past Museum, Puerto Morelos, Mexico

The Weeks Formation preserves a diverse, yet largely undescribed, exceptionally preserved fauna of late Guzhangian age (early late Cambrian). Recent investigations have shown that this fauna contains taxa previously regarded as typical of older or younger Konservat-Lagerstätten, which highlighted its transitional nature. Here we present two rare arthropods of uncertain affinities that further exemplify the uniqueness of the non-trilobite arthropod fauna of the Weeks Formation. Notchia weugi is characterized by a short cephalon, a trunk with 12 tergites and weakly differentiated into two morphological regions, and a spine-bearing rectangular telson. This taxon somewhat resembles other Cambrian arthropods, such as strabopids or Sidneyia, but detailed comparisons reveal many differences with them, arguing against close phylogenetic relationships. The affinities of Falcatamacaris bellua are even more problematic, for this large arthropod exhibits a mosaic of characters as-yet known in different groups of Artiopoda, along with unique features. The presence of a calcitic cuticle is particularly remarkable, being observed for the first time in a non-trilobite Cambrian arthropod. The discovery of these two taxa suggests that the Weeks Formation Konservat-Lagerstätte could significantly contribute to a better assessment of arthropod disparity in late Cambrian time.

Early animals flex their muscles: Haootia quadriformis n. gen. n. sp. interpreted as a late Ediacaran muscular cnidarian impression

^*Alexander G. Liu^1,2, Jack J. Matthews³, Latha R. Menon³, Duncan McIlroy⁴ and Martin D. Brasier^3,4

¹University of Bristol
²University of Cambridge
³University of Oxford
⁴Memorial University of Newfoundland

In recent years, biomarker and molecular studies have constrained the search for the earliest animal fossils to late Neoproterozoic fossil assemblages. Convincing Neoproterozoic body fossil evidence for members of recognisable metazoan phyla is scarce, and is mostly confined to latest Ediacaran strata younger than 555 million years in age. In older sections, fossil evidence for the presence of metazoans largely stems from ichnological data. We report a remarkable new fossil from the ~560 Ma Fermeuse Formation of the Bonavista Peninsula, Newfoundland. This specimen, found within a turbidite succession alongside frondose rangeomorph taxa more typical of late Ediacaran strata, possesses prominent bundles of fibrous ridges, four-fold radial symmetry, a basal holdfast disc, and bifurcating branches. Our analysis of bundle arrangements, fibre morphology, and taphonomy suggest that the fibrous bundles are consistent with the muscular structure of a benthic cnidarian organism possessing a gross morphology that invites comparison with living stauromedusans. The organism, Haootia quadriformis n. gen. n. sp., is thus interpreted as a stem group cnidarian. Such an interpretation has significant implications for both the study of early animal evolution, and for our understanding of ecological complexity within late Ediacaran marine ecosystems.

Understanding taphonomic variance between fern and seed fern preservation from the Mazon Creek Lagerstätte

^*Emma R. Locatelli¹, Marc Laflamme², Laura Krajewski², Allen V. Chochinov², Komal Pawar², Jezrel Torres² and Benjamin Tsang²

¹Yale University
²University of Toronto Mississauga

Plant fossils from the Mazon Creek Lagerstätte (307 Ma) represent a rare window into the ecosystem of the late Paleozoic. Biases introduced during fossilization may have impacted the flora by selectively preserving particular taxa, inhibiting our ability to utilize the Mazon Creek flora in interpreting the vegetation of the region.  Comprehensive databases were constructed by scoring morphologic and taphonomic characters from several hundreds of fern and seed fern fossils in the collections of the Royal Ontario Museum in Toronto. The datasets were analyzed using logistic regression to identify important parameters affecting the preservation of the two groups and to better understand how the flora represents the paleoenvironment.

Initial results indicate a systematic bias in favor of the preservation of seed fern foliage in terms of completeness and retention of important morphological characters. Ferns, in contrast, tend to be more poorly preserved in terms of morphology and little to no organic material survives. This difference in preservation is attributed to variation in the rate of decay between the two groups. Detailed evaluations like this of discrepancies in preservational quality within Lagerstätten will aid in identifying and understanding taphonomic biases that may compromise evidence of the history of life on Earth.

Effect of carbon dioxide concentration on the digestibility of possible sauropod food plants.

Barry Lomax¹, Fiona Gill² and Jürgen Hummel³

¹University of Nottingham
²University of Leeds
³University of Göttingenz

During the Mesozoic, atmospheric carbon dioxide levels were elevated when compared to the present day, with estimates ranging from ~650 to ~1130ppm. Elevated carbon dioxide leads to accelerates plant growth via the production of carbohydrates.  These changes in turn may affect the fibre content, carbohydrate to protein ratio, secondary metabolite profiles and other properties related to digestibility. We therefore hypothesize that the elevated carbon dioxide levels during the Mesozoic may have resulted in variations to the digestibility of Mesozoic plants and that these changes may have cascaded up the food chain.  To test this hypothesis we investigated the effect carbon dioxide had on the digestibility of living fossils plant species which are modern analogues to sauropod food.  Plants were grown under a range of Mesozoic carbon dioxide concentrations (400 ppm, 800 ppm, 1200 ppm and 2000 ppm), with all other growth parameters held constant. The metabolizable energy content of the plants as a measure of digestibility was evaluated using the Hohenheim gas test. Data show that metabolizable energy content varied considerably between plant species, but no systematic changes as a function of carbon dioxide were found. Variations in diet quality available to sauropods throughout the Mesozoic may have implications for our understanding of sauropod digestion, energy requirements and potentially methane emissions.

Flexure of microbial mats around holdfasts of epibenthic fronds: Ediacaran ecology in the Cambrian of Avalonia (Ireland)

^*Breandán Anraoi MacGabhann^1,2,3, Paul D. Ryan³ and John Murray³

¹Department of Geography, Edge Hill University
²School of GeoSciences, University of Edinburgh
³Earth and Ocean Sciences, National University of Ireland, Galway

The Cambrian Explosion was accompanied by a fundamental shift in the nature of marine substrates. In shallow marine environments, characteristic Neoproterozoic microbial matgrounds gave way to typical Phanerozoic mixground substrates, concordant with the evolution of widespread bioturbation. In deep marine environments, the 'agronomic revolution' appears to have been delayed, as suggested by strata such as the microbially-bound middle Cambrian contourites of the Booley Bay Formation, southeastern Ireland.

Two sets of non-mineralised discoidal structures occur in this unit; millimetre-scale scratch circles, and centimetre-scale partial discs preferentially orientated in the palaeocurrent direction. We investigated the hypothesis that the larger discs were holdfasts of frond-like organisms, preferentially orientated by current pressure on their upper parts, numerically modelling the flexure of a microbial mat around such a holdfast. While highly speculative, the models predict profiles consistent with field observations. We conclude that one admissible interpretation is that the Booley Bay Formation preserves evidence of large stalked frond-like organisms, living in a contour-current environment, anchored to the microbially-bound substrate by discoidal holdfasts. The ecological similarity to deep marine Ediacaran environments such as Mistaken Point suggests that not just Ediacaran matgrounds, but Ediacaran community palaeoecology, survived in deep marine settings until at least the Middle Cambrian.

4D-Virtopsy and taphonomy of an Oligocene mole from the fossil site of Enspel (Germany)

^*Bastian Mähler¹, Achim H. Schwermann¹, Michael Wuttke², Julia A. Schultz¹ and Thomas Martin¹

¹Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Universität Bonn, Nußallee 8, 53115 Bonn, Germany
²Referat Erdgeschichte, Generaldirektion Kulturelles Erbe Rheinland-Pfalz, Große Langgasse 29, 55116 Mainz, Germany

Taphonomic experiments and µ-CT-analyses of extant Talpa europaea provide a closer look into the decay process of small mammals under fresh water conditions. Carcasses floated on the water surface and after a few hours sank to the bottom. At the same time decomposition of soft tissues began and putrefaction gas was produced. Consequently, carcasses bloated and re-floated to the water surface. The gas filled body cavities were 3D reconstructed and volumes were measured. The higher the temperature the faster gas formation and decomposition of soft tissues occurred. With ongoing decomposition, the skeleton was successively disarticulated and disconnected parts were scattered. These observations were used for a taphonomic interpretation of the partial skeleton of an Oligocene mole (Geotrypus antiquus) from the fossil site Enspel in Germany. The positions of anterior limbs, the presence of distal hand elements and left femur in addition to an articulated mandible with occluding teeth indicate that an almost completely articulated specimen sank to the ground, without extended period of floating. After decomposition of most soft tissues some bones were shifted to the left side of the body axis by an underwater current before the skeleton was finally buried.

Exploring the cranial and endocranial anatomy of a Jurassic ichthyosaur using digital techniques.    

^*Ryan RDM Marek¹, Benjamin BCM Moon¹ and Michael MJB Benton¹

¹University of Bristol

The bicentennial anniversary of the first scientific description of an ichthyosaur is celebrated in 2014. Even after 200 years of study, some details of their cranial anatomy are still unclear. This has implications for understanding the ichthyosaurian phylogeny, and also the function of their skull. Based on computed tomographic (CT) scans of a nearly complete ichthyosaur (Hauffiopteryx typicus) skull from the Toarcian of Strawberry Bank, England, elements of cranial anatomy are described, and the occipital region is fully reconstructed, creating the first digital cranial endocast of an ichthyosaur. This endocast reveals evidence that by the Early Jurassic, ichthyosaurs had neuroanatomical adaptations that allowed them to be highly mobile, visual predators in the aquatic realm, with enlarged optic lobes and an enlarged cerebellum. Surprisingly, the olfactory region also appears to be enlarged, leading to the conclusion that olfaction was more important in the lives of ichthyosaurs than previously believed, perhaps because it had to be assumed that the nostrils had to be closed when the animal was submerged. A brief phylogenetic analysis confirmed the initial placement of this specimen as either H. typicus or a closely related sister taxon, which is also supported by many broader aspects of the cranial anatomy. 

Muscle-powered helens, the missing piece of hyolithid body construction

Monica Marti Mus¹, Lennart Jeppsson² and John M. Malinky³

¹Universidad de Extremadura, Badajoz
²Lund University
³San Diego City College

Hyolithids are a group of Palaeozoic lophotrochozoans with a four-pieced skeleton consisting of a conch, an operculum, and a pair of lateral ‘spines’ named helens. These later elements are fragile and their morphological details have remained relatively poorly known. As a result, the functional morphology of hyolithids has remained problematic. The material presented herein, consisting of disarticulated, pyritised skeletal elements from the Silurian of Gotland, Sweden, includes the first complete, three-dimensionally preserved helens. The material confirms that helens were massive skeletal elements, whose growth started proximally, in an epithelial invagination, with the deposition of a central lamella. Further shell accretion took place around this lamella, but followed a particular accretion pattern seemingly constrained by the presence of marginal muscle attachment sites on the proximal-most portion of the helens. Diverse and abundant muscle scars had been previously documented on the conch and operculum of hyolithids, but had never been reported on the helens. The location of these attachment sites is coherent with a wide and independent range of movements for the helens, which could have acted as oars, as stabilizers, and to orient and lift the conch aperture.

Tectonic Forcing of Biogeochemical Cycles and Marine Biodiversification

Ronald E. Martin¹

¹Department of Geological Sciences, University of Delaware, Newark, DE 19716, USA

Igneous activity associated with seafloor spreading and mountain building has impacted nutrient input to the oceans and marine biodiversity through geologic time.  Tectonic cyclicity during the Phanerozoic Eon is coupled to the evolution of the biogeochemical cycles of carbon and sulfur and marine biodiversification.  Tectonism associated with the emplacement of large igneous provinces (LIPs) enhanced the input of phosphorus from the continents to the oceans on approximately 30-to-60-million-year periodicities, stimulating primary productivity and the pelagic rain of organic matter, thereby affecting redox conditions and phosphorus availability. These findings appear to cross-correlate with cycles of marine biodiversification on similar durations.  Oceanic anoxic events and mass extinction result from similar processes on shorter time scales. The impact of these biogeochemical processes on marine biodiversification therefore appears to be scale-dependent.

Late Ordovician (early Katian) trilobite faunas from the Myatas Formation, North Central Kazakhstan

Lucy M. E. McCobb¹ and Leonid E. Popov¹

¹National Museum Wales

The trilobite collections of the late Michael K. Apollonov include faunas from two Late Ordovician localities, both in the Myatas Formation, exposed on the northern shores of Atansor Lake in northern Central Kazakhstan. The older, oligotaxic fauna derives from flanks of a carbonate build-up. It is dominated by numerous Sphaerexochus specimens.  Amphilichas is also relatively common, with Pliomerina and the asaphid Farasaphus? present as rare components. The overlying unit of siliceous argillites contains a different assemblage, representing the raphiophorid biofacies and comprising seven genera.  The fauna is dominated by blind trilobites (a trinucleid, a three-segmented raphiophorid, Malongullia?, Lonchodomas and Arthrorhachis) and three species of large-eyed Telephina, suggesting that they occupied the disphotic zone in deep water offshore.  A single cranidium of the odontopleurid Primaspis is also present.  The trinucleid has an unusual pit arrangement, with E₁ and E₂ aligned in sulci and all I arcs irregularly arranged, and likely represents a new genus. The Atansor area is located within the Stepnyak tectonostratigraphical unit, which probably represented an Ordovician active margin of the the Kalmykkol-Kokchetav Microplate.

The GB/3D Type Fossils Online Web Portal

Tim McCormick¹, Michael PA Howe¹ and Simon J Harris¹

¹British Geological Survey

From 2011 to 2014 the British Geological Survey has been leading a consortium of UK museums to construct the web portal at www.3d-fossils.ac.uk.  This gives access to metadata and high resolution ‘flat’ and stereo images of over 16,000 type macrofossil specimens from the UK.

We have made 3d digital models of approximately 10% of the fossils either by scanning them with portable ‘NextEngine 3D HD’ scanners or by photogrammetry.  These 3d models can be downloaded as zipped files from the website, or viewed and manipulated directly on screen using current web browsers.  We use a Makerbot 3d printer to make physical replicas of fossils which can be used for research, education and outreach.

The resources may be freely downloaded from the website and used subject to a Creative Commons Attribution ShareAlike Non-Commercial licence.

In practice the website is currently most useful to the professional palaeontologist who can use it to discover the whereabouts of the type specimens of a taxon, and to assess the completeness and preservation quality of the material.  Future development is likely to focus on improving functionality for public education and outreach. 

The hidden diet of cephalopods revealed by scratches, pits and stable isotopes

Alistair J McGowan¹, Christina Sprinks², Peter Chung², Rona McGill³ and Alistair J. McGowan⁴

¹GES,University of Glasgow
²GES, University of Glasgow
³SUERC
⁴BioGeoD

The feeding ecology of living cephalopods, and their extinct relatives, is underdetermined. While most living cephalopods are predators or scavengers, compositional data about their diets are limited by two factors: 1) Near complete pulping of their food prior to swallowing; 2) Only a small proportion of wild-caught cephalopods yield stomach contents. We propose that a combination of microwear and stable isotope analyses could yield considerable additional information on the diet of extant cephalopods. SEM images of beaks of common and bob-tailed squid were analyzed for differences in microwear. C and N stable isotope analyses were then performed on two beaks of each species. Significant, interpretable differences were found in the proportion of scratches and pits between the two species, demonstrating that microwear is a suitable tool for dietary analysis in cephalopods. Stable isotope work on extant cephalopods has already been revealing about trophic differences but this is the first attempt to match microwear to trophic level. This conservation palaeobiological approach could help with the analysis of fisheries food webs, as the removal of fish of similar body-size could allow cephalopods to increase their dominance of these ecosystems.

Extinction in the ocean but not on land – tracing the late Silurian Lau event in Sweden

K Mehlqvist¹ and V Vajda¹

¹Dept. of Geology, Lund University, Sweden

Upper Silurian successions from Sweden occur both on the island Gotland, situated in the Baltic Sea, and in the southern province Skåne. These sediments are generally near shore marine to intertidal lagoonal based on the low, but persistent occurrence of acritarchs together with the high relative abundance of spores through the main part of these successions (Mehlqvist et al , 2012, 2014).  Upper Silurian marine deposits are characterized by extreme conditions manifest by increase of cyanobacteria, cerebroid ooids, evaporite tracers combined with extinctions of conodont faunas and fish. These changes are not reflected in the terrestrial vegetation, which instead reflect a robust, well-established and stable early flora throughout the studied succession represented by the biostratigraphically important species including Synorisporites ? libycus, Hispanaediscus verrucatus, H. major, H. lamontii, Scylaspora scripta and Artemopyra radiata.

Mehlqvist, K., Vajda, V., Steemans, P., 2012. GFF 134, 133–144.

Mehlqvist, K., Larsson, K., Vajda, V., 2014. Review of Palaeobotany and Palynology 202, 1–14

 The Evolution of Speed

^*Tom Merrick-Fletcher¹, John D Altringham², Jeff Peakall¹, Paul B Wignall¹, Robert M Dorrell¹ and Gareth M Keevil¹

¹School of Earth and Environment, University of Leeds
²School of Biology, University of Leeds

Thelodont and acanthodian scales exhibit remarkable convergence with those of modern sharks, whose functions include drag reduction, abrasion defence, parasite resistance, and luminescence. Of these, drag-reduction has been a focus in biomechanical and engineering investigations particularly the riblets that ornament the dermal denticles of pelagic sharks. These structures are known to reduce skin friction by up to 10%, improving the efficiency and speed of movement. Modern shark scales have significantly narrower riblet spacing in faster-moving species, implying a functional optimum for higher speeds. Furthermore there is no significant difference between the riblet spacing of fast modern sharks, thelodonts, and acanthodians.

More broadly, scales along the flank may be inducing turbulent flow on purpose to delay boundary layer separation (stall), and reduce wake. To test this, and the efficacy of riblets in fossil taxa, flume studies were performed on plates of rapid prototyped Palaeozoic fish scales. Laser Doppler anemometry revealed that the majority of morphologies did not reduce flow velocity relative to the smooth control plate. This suggests that even without riblets ornamenting the crowns, having a rougher scale surface helps reduce drag. Our results demonstrate that novel and sophisticated drag-reduction adaptations existed at a remarkably early stage of vertebrate evolution.

Early forest soils from the Middle Devonian of New York State

^*Jennifer L. Morris¹, David Beerling¹, William Stein², Chris Berry³, John Marshall⁴, Charles Wellman¹ and Jonathan Leake¹

¹Animal and Plant Sciences, Sheffield University, Sheffield, UK
²Dept. of Biological Sciences, Binghamton University, Binghamton, USA
³School of Earth and Ocean Sciences, Cardiff University, Cardiff, UK
⁴Ocean and Earth Science, University of Southampton, Southampton, UK

A Middle Devonian (Givetian) palaeosol horizon at Cairo Quarry, New York, has provided an opportunity to study the in situ roots of an early forest ecosystem, as well as the nature and degree of influence they had on weathering and soil development. The morphology and distribution of roots across this surface was mapped by Stein et al., and identified as belonging to archaeopteridalean progymnosperm (Archaeopteris) and cladoxylopsid pseudosporochalean (Wattieza) trees.  

An assessment of rooting depth and root morphology of these two tree types, as well as their influence on weathering, is obtained from detailed sedimentological and geochemical studies of the palaeosol beneath. 18 cores were drilled near the bases of archaeopteridalean and cladoxylopsid rooting structures of different sizes. The palaeosol is interpreted as a palaeo-Vertisol, with a maximum thickness of 1.66m. Four groups of rhizoliths are recognised based on their size, orientation and morphology and assigned as either archaeopteridalean or cladoxlopsid. There is a positive relationship between archaeopteridalean tree size and rooting depth, up to 1.61m. Wattieza roots do not exceed 30 cm depth, with no correlation to tree size.

Using ICP-MS, elemental distributions and molecular ratios down the palaeosol profile are used as proxies for weathering and pedogenic processes.

Local diversity hot spots in the Middle Miocene of the Central Paratethys: influence of environment and sampling

^*Rafal Nawrot¹, Martin Zuschin¹, Mathias Harzhauser², Andreas Kroh² and Oleg Mandic²

¹Department of Palaeontology, University of Vienna, Vienna, Austria
²Natural History Museum Vienna, Vienna, Austria

Species richness captured by historical fossil inventories is a complex function of true local diversity, degree of outcrop-scale heterogeneity in species composition and sampling intensity. The molluscan fauna of Lapugiu de Sus (Hunedoara District, Romania) constitutes one of the most diverse Early Badenian (Langhian) assemblages of the Paratethys Sea, with almost one thousand species reported during 170 years of extensive studies. We evaluate whether this exceptional local richness reflects the actual diversity hot spot or just a long history of fossil-collecting by comparing the fauna of Lapugiu with other Paratethyan lagerstätten of similar age using literature-derived species lists and bulk-sampled abundance data (42 samples, 24,000 specimens, and 530 species from 6 localities). Sampling-standardized richness estimates for samples from Lapugiu are all consistently high, reflecting higher evenness and more offshore dispositional setting compared to most of other studied sites. Nevertheless, individual samples from other localities can exhibit comparably high diversity levels, in spite of generally lower diversity at the outcrop-scale when all samples are pooled. At least 3-4 times greater number of species previously reported from Lapugiu may be, therefore, a result of the bonanza effect, where uniformly species-rich deposits were attracting intensive palaeontological studies.

Dimorphism within the bivalved arthropod Isoxys from the Early Cambrian Sirius Passet lagerstätte, North Greenland.

^*Morten L. Nielsen¹ and Jan. A. Rasmussen²

¹Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark. E-mail bvm328@alumni.ku.dk
²Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark. E-mail janr@snm.ku.dk

More than 250 specimens of the Early Cambrian arthropod Isoxys have been analysed morphometrically. Rare specimens are characterized by preserved soft anatomy such as eyes, but in most specimens only features related to the spines, inner lamellae and the bivalved carapace are preserved. Morphometrical analyses shows that Isoxys from North Greenland may be divided into two main morphological groups, particularly distinguished by differences in the relative width of the doublure (Wd). The relative doublure width is computed as the height of one valve (H) divided by the maximum width of the doublure (H/Wd). In the two morphogroups, H/Wd is independent of both the total size and the stratigraphical position of the specimen in the section. F- and t-tests show that the two main morphogroups are significantly different from each other by means of both H/Wd and the length/height ratio. The dimorphism is probably related to sexual dimorphism or the presence of two distinct species. The holotype of Isoxys volucris Williams, Siveter & Peel, 1996 belong to the most abundant morphogroup distinguished by a relatively wide doublure.

Palaeoenviromental reconstruction from well-preserved Mississippian brachiopod shells.

^*Leah S P Nolan¹, Melanie J Leng², Lucia Angiolini³, Sarah J Davies¹, Flavio Jadoul³, Vanessa J Banks², Sarah E Gabbott¹ and Michael H Stephenson⁴

¹University of Leicester, Department of Geology, Leicester, UK.
²British geological Survey, Nottingham, UK.
³Universita degli Studi di Milano, Dipartimento di Scienze della Terra, Milano, Italy
⁴British geological Survey, Nottingham, Uk.

Stable isotopes (δ¹⁸O, δ¹³C) of biogenic calcite are frequently used for assessing palaeoenvironment and palaeoclimate. Preservation of primary calcite needs to be assessed prior to isotope studies to ensure that data generated reflects original seawater chemistry, rather than secondary diagenetic fluids. Preservation analysis encompasses a range of techniques, including scanning electron microscopy, cathodoluminescence microscopy, and analysis of trace element abundance (Mn, Fe, Sr, etc). There are however, no fixed criteria for classifying biogenic calcite as pristine using these techniques, although it is best practice to use material which has passed most screening tests. Here a systematic procedure is outlined for analysis of Mississippian biogenic calcite from gigantoproductid brachiopods collected in the UK. A set of criteria are established based on these tests as well as subsequent high resolution isotope analysis (sampling individual growth bands). Where pristine calcite is identified we calculate seasonal sea surface temperatures through the organism’s life-time. This, combined with a detailed sedimentology investigation, enables the identification of preferred environments of Gigantoproductus species and helps understand why they dominate such deposits. This study provides a practical methodology, linking quantitative and qualitative data, and will allow a detailed palaeoenviromental reconstruction of this region of Mississippian palaeoequatorial Britain.

The messaoudensis-trifidum acritarch assemblage in the Lower Ordovician Fezouata Shales of Morocco

^*Hendrik Nowak¹, Mustapha Akodad², Bertrand Lefebvre³ and Thomas Servais¹

¹CNRS-UMR 8217 Géosystèmes, Université Lille1, U.F.R. des Sciences de la Terre, Bâtiment SN5, Avenue Paul Langevin, 59655 Villeneuve d’Ascq Cedex, France
²Faculté Multidisciplinaire de Nador, Labo OLMAN-RL, FPN 300, Selouane 67200, Nador, Morocco
³CNRS/ENS-UMR 5276, Université Lyon 1, Campus de la Doua, 2, rue Raphaël Dubois, 69622 Villeurbanne Cedex, France

The upper Tremadocian to lower Floian messaoudensis-trifidum acritarch assemblage was first described from the Skiddaw Group of England and subsequently from several localities on the Gondwanan margin that were positioned in high southern latitudes during the Early Ordovician. Here we report its presence in south-eastern Morocco, from surface samples from the Zagora area in the Draa valley and from the subsurface below Adrar Zouggar mountain. The corresponding strata belong to the Tremadocian to Floian Fezouata Shales. Six acritarch species/form groups that are typical of the Skiddaw Group assemblage were identified: Acanthodiacrodium? dilatum, Cymatiogalea messaoudensis, C. velifera, Caldariola glabra glabra, Stelliferidium trifidum and Veryhachium lairdii s.l.. The presence of Cymatiogalea velifera indicates a Tremadocian age. The absence of Coryphidium and Veryhachium trispinosum (Eisenack 1938) Stockmans & Willière 1962 would be consistent with the messaoudensis-trifidum sub-assemblages 1 and 2. This corresponds to the Araneograptus murrayi or Hunnegraptus copiosus graptolite zones.

Conservation of pyritized Autunian shale : Framboïdal pyrite, pyrrhotite and sulphur as source of degradation

^*Giliane P. Odin^1,2, Georges Gand³, Sébastien Steyer² and Véronique Rouchon¹

¹Centre de Recherche sur la Conservation des Collections (MNHN-CNRS-MCC, USR 3224) 36 rue Geoffroy Saint Hilaire 75005 Paris, France
²Centre de Recherche sur la Paléodiversité et les Paléoenvironnements (MNHN-CNRS-UPMC, UMR 7207), CP 38, 8 rue Buffon, 75005 Paris, France
³Biogéosciences (Université de Bourgogne, CNRS, UMR uB6282), 6 Bd Gabriel, 21000 Dijon, France

Some collections of French museums (MNHN, Paris; MHNA, Autun) include many fossils preserved within Autunian shale. Those containing unstable sulphur compounds (like pyrite, FeS₂) oxidize, resulting in iron sulphates efflorescence.

To better understand the processes underlying these degradations, a study was made on material from the Autun Basin (Saône-et-Loire, France; Permian) on both damaged historical specimens (“HS”; characteristic of a final state), and on new excavated samples (“NS”; comparable to an initial state). Presence and reactivity of iron and sulphur were studied and completed by artificial ageing, supposed to accelerate the degradation.

Iron was found to be mainly present in clays, partly as pyrite or sulphates. Similar amount of Fe²⁺ between HS and NS seems to imply a weak oxidation of iron. Sulphur occurs mostly as sulphates in the shale and as reduced reactive compounds in organic matter (“OM”). Gypsum (CaSO₄.2H₂O) is the main product obtained by artificial ageing of NS free from OM. Damaging iron sulphates are reproduced in NS presenting, at the shale/ OM interface, framboïdal pyrite, pyrrhotite and sulfur. This configuration was also detected in HS and should be used for the determination of fossils possible oxidation. Current investigation regards now the evaluation of conservative treatment.

Homology of cephalic sclerites in Burgess Shale euarthropods recognized through comparative palaeoneurology

^*Javier JOH Ortega-Hernández¹

¹University of Cambridge

The evolutionary transition from soft-bodied lobopodian-type taxa (lobopodians, gilled-lobopodians, radiodontans) to completely sclerotized euarthropods (e.g. fuxianhuiids, artiopodans) is partially reflected by a substantial rearrangement of the segmental organization of the head region. Although advances in palaeoneurology and developmental biology have provided some clarity on the serial homology between cephalic limbs in stem and crown-group euarthropods, such comparisons are less straightforward when dealing with non-appendicular exoskeletal structures. The recent description of the brain morphology in the Chengjiang radiodontan Lyrarapax unguispinus, however, draws attention to a fundamentally similar organization of non-appendicular and sclerotized anterior structures between lower and upper stem-Euarthropoda. A revision of the head region of exceptionally preserved taxa from the middle Cambrian Burgess Shale suggests the existence of preserved neurological remains associated with the anterior sclerite and the stalked eyes, more specifically the presence of putative protocerebral ganglia. These observations support the homology of isolated sclerotized plates on the head region of radiodontans, and the ‘anterior sclerite’ observed in fuxianhuiids, bivalved Cambrian forms and phylogenetically basal artiopodans. These comparisons have direct implications for the formulation of characters used in phylogenetic analyses, and demonstrate that it is possible to recognize relationships of homology between exoskeletal features in taxa with a fundamentally distinct body organization. 

First Lower Cambrian record of Wiwaxia from north-west Gondwana: small carbonaceous fossils from the Lancara Formation, Cantabrian Mountains, northern Spain

Teodoro Palacios¹, Sören Jensen¹, ^*Iván Cortijo Sánchez¹ and Mónica Martí Mus¹

¹Universidad de Extremadura, Badajoz

Sclerites of the bilaterian metazoan Wiwaxia are here reported from the upper part of the lower member of the Lancara Formation in the Porma area, Cantabrian Mountains, northern Spain. The material is preserved as small carbonaceous fossils extracted from fine-grained siliciclastic interbeds in dolostone levels. Earlier reports of scarce trilobites and archaeocyaths from the upper part of the lower member of the Lancara Formation in other sections in the Cantabrian Mountains have been assigned to the late Early Cambrian Bilbilian regional stage. New biostratigraphical age constraints come from acritarchs in the Wiwaxia-bearing samples, which include Skiagia ciliosa, S. compressa, S. orbiculare, and Globosphaeridium cerinum, an association restricted to the Heliosphaeridium dissimilare – Skiagia ciliosa Zone, suggesting late Cambrian Age 3 or early Cambrian Age 4. This is only the second record of Wiwaxia from Cambrian rocks of north-west Gondwana, with a previous report from Cambrian Stage 5 beds of the Czech Republic. Wiwaxia spans the Lower to Middle Cambrian transition in Laurentia and South China and now also in north-west Gondwana.

High-resolution vegetation and climate fluctuations during the Late Pliocene derived from the palynological record of ODP Site 642B, Norwegian Sea

^*Sina SP Panitz¹, Ulrich US Salzmann¹, Stijn SD De Schepper², Bjørg BR Risebrobakken² and Emma EH Hocking¹

¹1Department of Geography, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
²Bjerknes Centre for Climate Research, Uni Research Climate, Allégaten 55, N-5007 Bergen, Norway

During the warmer-than-present Late Pliocene, warming was particularly accentuated at high latitudes. Most recent data-model comparison studies identified weaknesses in the reconstruction of high latitude climate variability due to the insufficient resolution of terrestrial records.

In order to resolve these uncertainties, we present high-resolution vegetation and climate reconstructions for the subpolar marine sediment core ODP Site 642B, Norwegian Sea for the Late Pliocene.

Initial results show that the Late Pliocene (3.53-3.14 Ma) is marked by an expansion of wetlands and deciduous woodlands at the expense of cool temperate pine forests. An opening of the pine forests is indicated by an increase in the relative abundance of Asteraceae and Poaceae between 3.45 and 3.26 Ma. Thereafter, the decrease in Pinus percentages and the increase in Sphagnum and abundance of deciduous trees (Alnus, Betula, Corylus, Quercus, Ulmus) indicate a spread of moist mixed forests, suggesting wetter climate conditions.

Using the Coexistence Approach the forest-dominated intervals are associated with temperatures on average 7-8.5°C higher than present. The expansion of open grasslands is accompanied by cooler, but still 2.5 to 4°C warmer-than-present temperatures. This initial climate reconstruction will be refined by incorporating data on mean annual precipitation and seasonal temperatures.

A stable isotopic investigation of chemosymbiosis through geological time

^*Edine Pape¹, Fiona L. Gill¹, Crispin T.S. Little¹ and Robert J. Newton¹

¹University of Leeds

To investigate the palaeobiology of fossil invertebrates, our research aims to directly reconstruct nutritional strategies of bivalves, gastropods and brachiopods, by looking at the stable isotopic signatures of the organic matter preserved in fossil shells. Two other research projects are presented by Elms et al. and Stirk et al. (2014, this volume).

Shells consist of calcium carbonate minerals enclosed by a three-dimensional organic framework, the shell-bound organic matter (SBOM). Modern SBOM has similar carbon, sulphur and nitrogen isotopic values to the animal’s soft tissues that reflect feeding strategies. Differentiation between feeding strategies is possible because the isotopes track both trophic level and isotopic source; in particular it shows the distinct reduced values of sources needed for chemosymbiosis. The chemosynthethic bacteria living in chemosymbiosis with invertebrates use these chemical compounds to obtain energy (see: Stirk et al.).

Our project focuses on chemosymbiosis through geological time. Despite the importance of chemosymbiosis at modern vents and seeps, its origin and evolutionary history are poorly understood. We present SBOM isotope data from modern and fossil bivalves and brachiopods across a range of feeding strategies, and fossil SBOM signatures allow investigation of the relationship between chemosymbiosis and the evolution of seep and vent fauna.

Harpax spinosa (Bivalvia: Plicatulidae) a preferred prey target for drilling predators during the Pliensbachian (Lower Jurassic) time?

^*R. Paredes¹ and E. M. Harper²

¹Palaeontology Department, Earth Sciences Faculty, Complutense University of Madrid, C\ José Antonio Novais, 2, 28040-Madrid, Spain
²Earth Sciences Department and Sedgwick Museum, University of Cambridge, Downing Site, Cambridge, CB2 3EQ, United Kingdom

Several instances of Jurassic bivalves bearing gastropod-like drillholes have been documented in the last decades. However, only a few of them are from the Lower Jurassic. It is still under debate who were their producers, since none of the known drillers like carnivorous gastropod extend into Jurassic. Temporally and geographically constrained predated material from England and Iberia (Central Spain and Portugal) has been reported. The bivalve plicatulid Harpax spinosa (Sowerby) has been revealed as a common prey taxon from two-valved macrobenthic organisms (bivalves and brachiopods) from the various assemblages we have studied. This is despite any deterrent effect of the spinous ornamentation of the left valve. Data show that 10 drilling predation levels at two Pliensbachian (Margaritatus Chronozone) Iberian sections ranges from <10%-22% in drilling frequencies. Those data seem to corroborate the idea that drilling frequency reflects abundance of predators in a particular habitat and a prey preference. A possible explanation to interpret this selection of small-sized prey could be a cost-benefit strategy by the predators. These chronostratigraphically well constrained evidences helps to emphasise the drilling predation during Pliensbachian time in England and the Iberian basins.

Cambrian Polychaetes and the Origin of the Annelid Bodyplan

^*Luke Parry^1,2, Gregory D Edgecombe² and Jakob Vinther¹

¹University of Bristol
²Natural History Museum

Annelid worms are segmented metazoans that are important components of ecosystems spanning terrestrial realms to the deep sea, and have a fossil record extending to the early Cambrian. They are remarkably diverse, possessing high taxonomic diversity and exceptional morphological disparity having evolved numerous feeding strategies and ecologies. Their interrelationships and evolution have been a source of controversy over the past century, with the composition of the crown group, internal relationships and the body plan of the ancestral annelid having undergone major revisions. Burgess Shale-type Lagerstätten are critical for understanding the assembly of the body plans of metazoan phyla, but the relationship of Cambrian polychaete body fossils to living annelids has remained obscure. We present new observations from Sirius Passet and from the Burgess Shale including new taxa, muscle anatomy and the head organization of the oldest annelids. Their simple parapodia, heads and chaetae suggest that they lie outside of the crown group forming a paraphyletic grade, allowing us to formulate a novel hypothesis for the origin of the annelid Bauplan. The Cambrian fossil record suggests that annelids are derived from an epibenthic ancestor that possessed simple chaetae, protective notochaetae, paired palps and paired longitudinal and circular muscle bands.

Palaeoecology of calcified metazoans from the Nama Group, Namibia

^*Amelia M. Penny¹, Rachel Wood¹, Andrew Curtis¹, Frederick Bowyer¹, Rosalie Tostevin² and Karl-Heinz Hoffman³

¹University of Edinburgh
²University College London
³Geological Survey of Namibia

The oldest known calcified metazoans are from the Ediacaran Period, around 550Ma. These metazoans are the first known adopters of the skeleton-building strategy which became widespread among metazoan taxa during the Cambrian. Three Ediacaran taxa, Cloudina, Namacalathus and Namapoikia, are locally abundant in shallow and mid-ramp settings of the Nama Group of southern Namibia, a mixed carbonate and clastic succession extending from around 552-541Ma.

New fossil material from the Nama Group permits new insights into the palaeoecology of these calcified metazoans. In particular, the Nama Group contains extensive microbial-metazoan reefs, where the presence of free-growing, reef-building Cloudina, as well as thrombolite-associated Cloudina and Namacalathus and fissure-dwelling Namapoikia, indicates a differentiation of metazoans into the distinct open surface and cryptic biotas characteristic of Phanerozoic reefs, with accompanying complex ecological interactions.

Ongoing work on the calcified metazoans of the Nama Group seeks to further investigate their palaeoecology, adding to the picture of ecological complexity in the early skeletonised metazoan communities of the Nama Group.

The first evidence of Mesozoic wrinkle structures (cyanobacterial mats) from Sweden

O Peterffy¹, M Calner¹ and V Vivi²

¹Department of Geology, Lund University, Sweden
²Department of Geology, Lund University

Microbial mats are formed by cyanobacteria, generally by multilayer microbial communities composed of different cyanobacterium species (Kershaw, 2012). When fossilized,  they are termed wrinkle structures - microbially induced sedimentary structures (MISS) and are relatively common in pre-Cambrian and Cambrian siltstones and sandstones but are otherwise rare in the Phanerozoic geological record. This paper reports on the first findings of Mesozoic wrinkle structures from Sweden.  These are preserved in fine-grained and organic-rich heterolitic strata of the basal Jurassic (Hettangian) Höganäs Formation in Skåne, southern Sweden (Vajda & Wigforss-Lange 2009). Palynological analyses performed on sandstones hosting the wrinkle structure itself shows that the local terrestrial environment most probably consisted of a wetland hosting ferns, cypress and the typical Early Jurassic pollen taxon, Classopollis produced by today extinct conifers (Vajda,  2001).  The palynostratigraphy indicates a Hettangian age, still within the floral recovery phase following the Triassic-Jurassic extinction event.  The finding of wrinkle structures is significant as the presence of microbial mats in the subtidal zone suggests decreased benthic biodiversity and suppressed grazing in shallow marine environments in the early aftermath of the end-Triassic mass extinction event.

Kershaw, S., et al., 2012. Geobiology 10, 25–47

Vajda, V., 2001. Acta Palaeontologica Polonica 46, 403–426

Vajda, V. & Wigforss-Lange, J. 2009. GFF 131, 5–23

There’s pollen (and gold) in them thar hills: Palynological evidence for a warmer boreal climate during the Late Pliocene of the Yukon, Canada

^*Matthew J Pound¹, Robert I Lowther², Jeff Peakell², Robert J Chapman² and U Salzmann¹

¹Northumbria University
²University of Leeds

The Late Pliocene (3.6 – 2.6 Ma) was a period of significant global warmth and it is considered a potential analogue for future anthropogenic climate change. Recent fieldwork in Bonanza Creek, Yukon has revealed a previously unknown fine grained sediment in gravel dominated stratum. The newly discovered fine grained sediments from between the gold bearing lower and upper White Channel Gravels have yielded a diverse assemblage of pollen and spores. The pollen assemblage recovered from the fine grained sediments of the White Channel gravels shows the presence of a taxonomically diverse mosaic environment in Bonanza Creek during the Late Pliocene.

Climate parameters were reconstructed using two different nearest living relative techniques. The mean annual temperature was at least 6°C warmer than modern, with significantly warmer winters and warm summers. Mean annual precipitation was greater than modern and rainfall was more evenly distributed throughout the year. The reconstructed climate of the Late Pliocene Bonanza Creek flora indicate an environment more akin to those 10° latitude further south today.

Reconstructing relationships of fossil jawless fish (Pteraspidiformes, Heterostraci)

^*Emma Randle¹ and Robert Sansom¹

¹University of Manchester

Fossil jawless vertebrates (stem-gnathostomes) are central to our understanding of vertebrate evolution, yet lack of understanding of their inter and intra relationships makes interpretation problematic. Key amongst those are the Heterostraci for which no reliable phylogenetic framework exists. For example, the inclusion of the Psammosteiformes within the larger Pteraspidiformes has long been debated, altering interpretations of heterostracan evolutionary histories. Here, a comprehensive analysis is made of the largest and most iconic clade of heterostracans, the Pteraspidiformes. Using a combination of observations of museum specimens and data from published literature, unique characters have been constructed and cladistic analysis applied using Mesquite and TNT. All described Pteraspidiformes genera (42) are included along with four out group taxa (Anglaspis, Nahanniaspis, Drepanaspis and Psammolepis). Psammosteiformes are found to belong with the Pteraspidiformes, positioned between the Anchipteraspididae and the rest of the Pteraspidiformes. This new phylogeny sheds light on a poorly understood clade, central to understanding of evolution of jawed vertebrates. Utilising this new phylogeny and stratigraphical and geographic occurrence of the taxa, dispersal histories are reconstructed in light of recent discussions regarding limited dispersal and endemism.

Plants and palaeoclimate: reconstructing past hydrological changes in the Neogene using plant compound isotopes

^*Rhian L. Rees-Owen¹, Robert J. Newton¹, Ruza Ivanovic¹, James B. Riding² and Jane E. Francis³

¹University of Leeds
²British Geological Survey
³British Antarctic urvey

Recent evidence from marine sediment records, as well as terrestrial glaciovolcanic sequences, suggest that duirng the late Neogene (14-2.5 Mya), the EAIS underwent periods of marginal retreatate in response to warmer climates. A suite of exceptionally well-preserved fossil wood fragments, identified as Nothofagus beardmorensis, has been recovered from palaeosol deposits in the Sirius Group sediments at Oliver Bluffs in the Beardmore Glacier region, Transantarctic Mountains, Antarctica (85° S). The fossils are ambiguously dated, but sit in this time period of interest.

Analysis of plant compound isotope ratios from these fossils (namely, cellulose and leaf waxes) provide unique insight into the global hydrological cycle during this vital part of Antarctica's history, allowing reconstruction of precipitation isotope ratios. This is the first time this technique has been applied to the Antarctic continent. Here, we present initial results from δ¹⁸O analysis of tree ring cellulose, which suggests the plants had access to precipitation that was significantly enriched (δ¹⁸O_precip = ~-15‰ for ancient; nbsp;δ¹⁸O_precip = -80 - -30‰ for modern) relative to precipitation at similar latitudes today. This has wide-ranging implications for our understanding of the hydrological cycle during this time period, implying that atmospheric circulation and moisture delivery patterns were markedly different.

A new species of early brachyuran crab (Late Bathonian, France) and episkeletozoans: palaeoecological insights

^*Ninon Robin¹, Barry Van Bakel², Jean-Loup D'Hondt³ and Sylvain Charbonnier⁴

¹Muséum national d'Histoire naturelle, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements CNRS-MNHN-UPMC. 8, rue Buffon, 75005 Paris.
²Oertijdmuseum De Groene Poort, Bosscheweg 80, NL-5283 WB Boxtel.
³Muséum national d'Histoire naturelle, UMR 7205, CNRS-MNHN-UPMC-EPHE, Institut de Systématique, Evolution, Biodiversité. 55 rue Buffon 75005 Paris
⁴Muséum national d'Histoire naturelle, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements CNRS-MNHN-UPMC.8, rue Buffon, 75005 Paris.

Early and Middle Jurassic crabs are rare and correspond to the earliest known brachyurans. We report here a new species of early Brachyura, from the Late Bathonian of Sarthe (France) that we describe as Tanidromites raboeufi, a homolodromioid crab. This specimen with a mostly well-preserved cuticle shows two epibiotic bryozoan colonies on its dorsal side, a unique fact for a representative of first brachyurans. One of these colonies seems settled on the internal side of the crab, indicating their probable post-mortem settlement and growth on the carapace of T. raboeufi. Colonies sizes indicate a growth lasting at least one month on this emptied carapace abandoned on the seafloor, what argues for a certain resistance of the carapace. This is noteworthy for Homolodromiodea, known in present-day environments for having very fragile carapaces. We identify bryozoans as young colonies of Reptomultisparsa incrustans, a Jurassic cyclostome specific of gastropod shells, inhabited by paguroids. This demonstrates that R. incrustans larvae were able to test several kinds of substrates for ensuring their growth (hard substrates emerging at the soft sediment surface, like carapaces of dead crabs or gastropod shells); but that only some of them enabled the complete proliferation of colonies (shells inhabited by paguroids). 

An enigmatic crinoid Pentamerocrinus Jaekel, 1918: Systematic position and possible structures of the aboral nervous system

^*Sergey V. ROZHNOV¹

¹Borissiak Paleontological Institute RAS, Moscow, Russia

Pentamerocrinus Jaekel, 1918, was described based on a single cup from the Middle Ordovician of the St. Petersburg. Incomplete preservation, unusual structure of the cup make difficult to determine its systematic position. The second cup, stored now in the Borissik Paleontological Institute, comes from Darriwilian (Azeri regional stage, Dubroviki Formation) near Volkhov town. The cup is large, wide, monocyclic with a complex radial C formed by inferradial and axillar superradial. Two facets are situated on the distal part of the superradial C. It can be assumed that the left facet served for the attachment of the anal tube. Such morphology suggests the possibility of the relationship of Pentamerocrinus with disparid crinoids Iocrinidae. Radials as well as brachials of the adjacent rays bonded together by a special lock - groove on one plate and a corresponding projection on the other. The ridges extending along the inner surface of the cup with channels quite exactly match the structure of the aboral nervous system of modern crinoids. Apparently, they reflect aboral nervous system structure.

The Enigmas of Phacopid Eyes

Brigitte Schoenemann^1,2 and Euan N.K. Clarkson³

¹University of Cologne, Zoology Institute, Dep. Neurobiology/Animal Physiology, Zülpicherstrasse 47b, D-50674 Cologne, Germany
²University of Bonn, Steinmann Institute (Palaeontology), Nussalle 8, D-53115 Bonn, Germany
³University of Edinburgh, Grant Institute, School of Geosciences, West Mains Road, Edinburgh EH9 3JW, UK

Trilobites are equipped with highly differentiated compound eyes which are present in the fossil record from the early Cambrian until the late Permian. Several  different types of these eyes are distinguishable by the pattern of their lenses, which are preserved often as a lattice of hexagons. Quite often the original calcitic lenses are retained. For a long time it seemed that nothing would ever be discovered about the internal structures of these ancient eyes, and thus about how they actually worked.  Using modern x-ray and synchrotron techniques, however,  it has proved possible recently, to establish the general structural principle of the schizochroal eyes of phacopid trilobites and to compare it with that of recent arthropods, especially with  the  visual system of Limulus (Schoenemann & Clarkson 2013). Besides this, there are other sublensar structural elements in phacopid trilobite eyes, not known so far in any Recent marine arthropods. Amongst other, we find muscles which might have allowed the lenses of these ancient compound eyes some degree of rotation,  and there are other enigmatic internal structures of the visual system which will be demonstrated and whose function will be discussed.

Schoenemann B. & Clarkson E.N.K. 2013 Scientific Reports, 3 : 1429

Identification of life-history stages in fusulinid foraminifera

Yukun Shi¹ and Norman Macleod^2,3

¹Natural History Museum London
²Nantural History Museum London
³Nanjing Institute of Palaeontology and Stratigraphy, Chinese Academy of Sciences, Nanjing, China

The whorls of fusulinid foraminifera preserve a record of each individual’s ontogeny, and therefore provide proxy access to morphological life-history patterns. Morphometric analysis has revealed that different fusulinid genera exhibit characteristically different, ontogenetic trajectories within a space defined by size, shape, and whorl number variables. In other groups, less dramatic ontogenetic transitions have been used to define juvenile, sub-adult, and adult life history stages. For example, whorl shape in Schwagerina turns progressively from a sphaerical to fusiform shape whereas Robustoschwagerina and Sphaeroschwagerina change from an early sphaerical character to a fusiform shape and then back to a sphaerical. More intriguing is our finding that, on occasion, the ontogenetic patterns of individuals assigned to the same species on the basis of superficial ‘adult’ morphology differ in characteristic and consistent ways. While care must be taken not to confuse pattern-level observations with process-level inferences, if additional investigations confirm the generality of these patterns they may enable fusulinids to be used to test a variety of developmental, taxonomic, phylogenetic, evolutionary, and ecological hypotheses. 

The Ediacaran–Cambrian transition: the record from small carbonaceous fossils (SCFs).

^*Ben J. Slater¹, Thomas H. P. Harvey² and Nicholas J. Butterfield³

¹Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB23EQ, UK. E-mail: bjs58@cam.ac.uk
²Department of Geology, University of Leicester, University Road, Leicester, LE17RH, UK. E-mail: thph2@le.ac.uk
³Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB23EQ, UK. E-mail: njb1005@cam.ac.uk

The emergence of metazoan-dominated ecosystems that characterize the Phanerozoic is arguably the most striking signal in the fossil record. The Ediacaran biosphere was already populated by an array of complex multicellular forms prior to the advent of the Cambrian, however, the origins of metazoans remains frustratingly obscure. Current perceptions of this transition are largely based on the record from mineralized components preserved as small shelly fossils (SSFs) and from spatiotemporally sparse lagerstätten such as the Burgess Shale and Chengjiang. Ideally a more cosmopolitan source of data is required. Small carbonaceous fossils (SCFs) provide an abundant source of information which complements the record from mineralized SSFs and lagerstätten. SCFs encompass an array of organic-walled fossils that represent the disarticulated remains of non-biomineralizing organisms. Often SCFs are too delicate to survive traditional palynological processing, but low-manipulation extraction techniques can yield abundant and morphologically informative fossils. SCFs recovered from mudrocks of the Baltoscandian Basin bridging the Ediacaran-Cambrian boundary were used to track biotic changes across this transition. Preliminary results support the case for a ‘Cambrian explosion’ of metazoans, with Ediacaran assemblages being characterized by forms attributable to the problematic ‘vendotaenids’ while earliest Cambrian sediments yield an increasing diversity of metazoan–derived elements.

Stable Isotopic signatures of modern chemosynthesis-based bivalves and gastropods associated with hydrothermal vents  

^*Emma B Stirk¹, Edine Pape¹, Fiona L Gill¹, Crispin T S Little¹, Robert J Newton¹, Cindy L Van Dover² and Christopher J Sweeting³

¹University of Leeds
²Duke University
³Newcastle University

This work is part of a larger project using stable isotopic signatures of organic matter preserved in fossil shells to reconstruct nutritional strategies (see: Pape et al. 2014 and Elms et al., 2014, this volume). One of these strategies is chemosymbiosis, well known from modern deep-sea hydrothermal vents. Chemosynthetic bacteria living symbiotically with vent invertebrates use methane and/or sulfur from vent fluids as an energy source for the fixation of carbon. This research investigates the relative contribution of environmental sources and chemosymbiosis-related fractionation to the stable isotopic signature of hydrothermal vent animals. We present stable isotope data from five bivalves and three gastropod chemosymbiotic vent species. Several species of Bathymodiolus were investigated from different locations within the East Pacific Rise, Manus Basin and Lau Basin to compare different environmental influences. Conversely, multiple species, namely Alvinoconcha hessleri and Ilfremeria nautilei, from the same locality were studied to compare different species under the same environmental conditions.

Our results provide insights into controls on the stable isotopic composition of soft tissue and shell-bound organic matter (SBOM) which can be applied to fossil shells in order to understand the evolution of chemosymbiosis and its relationship with changing seawater chemistry through geological time.

A Comprehensive Supertree of the Crocodylomorpha

^*Maximilian MTS Stockdale¹, Michael MJB Benton¹, Mario MB Bronzati², Marco MBA Andrade³ and Gavin GT Thomas⁴

¹School of Earth Sciences, University of Bristol
²Bayerische Staatssammlung für Paläontologie und Geologie, Paläontologie & Geobiologie LMU München
³Departamento de Paleontologia e Estratigrafia, Universidade Federal do Rio Grande do Sul
⁴Department of Animal and Plant Sciences, University of Sheffield

The crown-group Crocodylomorpha have an ecomorphology that is limited to amphibious ambush predators. During the Mesozoic and Cenozoic eras the stem-group Crocodylomorpha were represented by a much greater diversity of ecomorphologies, including exclusively marine, highly terrestrialised, insectivorous and herbivorous forms. The reason for the difference in diversity and disparity between stem- and grown-group crocodylomorphs is not clear. Crocodylomorphs have extensive crown- and stem-groups that are well represented in a fossil record of great longevity. Therefore the crocodylomorpha present a unique opportunity for studying large-scale evolutionary processes among amniotes. We present a new, comprehensive phylogeny of the crocodylomorpha assembled using the Matrix Representation Parsimony method. This phylogeny serves as a basis for a study of body size distribution and rates of transition within crocodylomorph groups using time-series and phylogenetic models.

Cracking Dinosaur Endothermy: Palaeophysiology Unscrambled

^*Maximilian MTS Stockdale¹, Michael MJB Benton¹ and Octávio OM Matteus²

¹School of Earth Sciences, University of Bristol
²Departamento de Ciências da Terra, Universidade Nova de Lisboa

The amniote eggshell is a respiratory structure adapted for the optimal transmission of respiratory gases to and from the embryo according to its physiological requirements. Therefore amniotes with higher oxygen requirements, such as those that sustain higher metabolic rates, can be expected to have eggshells that can maintain a greater gas flux to and from the egg. Here we show a highly significant relationship between metabolic rates and eggshell porosity in extant amniotes that predicts highly endothermic metabolic rates in dinosaurs. This study finds the eggshell porosity of extant endotherms to be significantly higher than that of extant ectotherms. Dinosaur eggshells are commonly preserved in the fossil record, and porosity may be readily identified and measured. This provides a simple tool to identify metabolic rates in extinct egg-laying tetrapods whose eggs possessed a mineralized shell. 

An investigation into ceramic technology and provenance using calcareous microfossils from Iron Age pottery at Burrough Hill hill fort, Leicestershire

^*Christopher P Stocker¹, Mark Williams¹, Ian P Wilkinson², Jeremy Taylor³ and Ian K Whitbread³

¹Department of Geology, University of Leicester, Leicester, United Kingdom
²British Geological Survey, Keyworth, Nottingham, United Kingdom
³School of Archaeological Studies, University of Leicester

One of the key questions in archaeology is the provenance of artefacts, and here micropalaeontology can play a key role. Previous palaeontological research on Iron Age ceramics from the East of England has focused on thin section petrography of pottery, demonstrating the widespread occurrence of foraminifera and ostracods. However, the identification of microfossils in thin section is complex and specialised. In this study thin section data are coupled with a novel technique for disaggregating calcareous microfossils from fired Iron Age pottery fragments at Burrough Hill hill fort in Leicestershire: the microfossils provide sufficient data for species-level identifications and suggest an origin for the pottery clays from the local Oadby Till. Experimental firing of the Oadby Till provides a comparative dataset for understanding the distribution and context of the microfossils and fabrics in the pottery at Burrough Hill.

Late Eocene to Oligocene vegetation and climate changes of Wilkes Land, East Antarctica (IODP Expedition 318)

^*Stephanie SS Strother¹, Ulrich US Salzmann¹, John JW Woodward¹, Francesca FS Sangiorgi², Peter PB Bijl², Alexander AH Houben² and Jörg JP Pross³

¹Northumbria University
²Utrecht University
³Heidelberg University

The Oligocene Epoch (33.9-23 Ma) is an important transitional period in Antarctica and little is known about the terrestrial response to global climate cooling. Here we present palynological results from site U1356 from Wilkes Land, East Antarctica (IODP 318). Preliminary results indicate that Late Eocene/Oligocene vegetation was dominated by temperate forest and shrub including Cyatheaceae, Microcachrys, Nothofagus, and Podocarpus. No major changes are found in the Late Eocene and early Oligocene pollen assemblages. However, increases in the taxa Phyllocladidites mawsonii and Dacrydiumites praecupressinoides indicate slightly warmer temperatures in the Late Eocene/Early Oligocene between ~45.5 and 33 Ma, with a decline observed in the Late Oligocene (~25-23 Ma)A greater abundance of reworked palynomorphs possibly indicate climate deterioration and increased glacial activity. Temperature reconstructions derived from the fossil pollen assemblages using the Coexistence Approach suggests mean annual temperatures between 6.7-13.7°C during the Late Eocene/Early Oligocene. The absence of Dacrydiumites praecupressinoides in most Late Oligocene samples suggests a drop of the minimum annual temperatures to 5.8°C. 

Computer Modelling of Heterochronic Change in Gastropod Morphology

Andrew R.H. Swan¹

¹Kingston University

Raup’s classic helicoid logarithmic spiral cone model is isometric, and hence organisms that approximate to this model cannot evolve a change in shape by heterochrony of the whole shell morphology. A computer model (HETEROSIM) is presented here in which Raup's parameters are permitted to change through ontogeny, and this allometric model is a good fit to a variety of gastropod species, especially Pulmonata. Simulated heterochrony (neoteny, acceleration, progenesis and hypermorphosis) can be applied to the generated shell shapes and a variety of sometimes surprising shapes can result. Suites of simulated shell shapes connected by heterochronic transformations often match well with the patterns of variation within gastropod families. The model can therefore engender hypotheses of heterochronic evolution that can then be tested against phylogenies. The model is also advocated as a stimulating pedagogic tool in teaching heterochrony.

Reassessing the Hirnantian macrofauna extinction in the central Anti-Atlas of southern Morocco

^*Lorena 1 Tessitore¹, Thijs R.A. 1 Vandenbroucke², Jean-François 2 Ghienne³, Marie-Pierre 3 Dabard⁴, Alfredo 4 Loi⁵ and David A.T. 5 Harper⁶

¹UMR 8217 du CNRS: Géosystèmes, Université Lille 1, France; lorena.tessitore@ed.univ-lille1.fr
²UMR 8217 du CNRS: Géosystèmes, Université Lille 1, France; thijs.vandenbroucke@univ-lille1.fr
³UMR 7516 du CNRS: Institut de Physique du Globe de Strasbourg, Université de Strasbourg, 1, France; ghienne@unistra.fr
⁴UMR 6118 du CNRS: Geosciences Rennes, Université de Rennes 1, France; marie-pierre.dabard@univ-rennes1.fr
⁵Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Italia; alfloi@unica.it
⁶Department of Earth Sciences, Durham University, England; david.harper@durham.ac.uk

The Hirnantian glaciation, one of the largest in the Phanerozoic, was long thought to have occurred in two phases, accompanying a double-phased extinction, respectively linked to the initial cooling and final melting of the ice sheets. Recent work, however, in high palaeolatitudinal settings, has identified a much more complex ‘Cenozoic style’ scenario for the Hirnantian glaciations, comprising over 15 high-order glacial cycles (Ghienne et al. 2014).

Our contribution aims to plot the entire macro- and microfauna record of the Central Anti-Atlas, southern Morocco, collected by Destombes (2004) against the revised architecture for the Hirnantian. Our database will allow us to evaluate if macro-faunal turnovers relate to other specific phases of the many glacial cycles. So far, our data compilation includes 150 species from 7 sites and up to 200 km of section. We report a decrease in faunal abundance and biodiversity, moving from Southwest towards Northeast, and through time, from the first glacial cycle towards the glacial maximum.

Destombes, J., 2004. Mémoire explicative des cartes géologiques au 200 000° de l’Anti-Atlas Marocain. Paléozoïque inférieur. Privately printed. 714pp.

Ghienne, J.F. et al. 2014. A Cenozoic-style scenario for the end-Ordovician glaciation. Nature Communications, 5: 4485.

Dinosaur trackways and palynology  from Maastrichtian deposits in Bolivia.

V Vajda¹

¹Department of Geology, Lund University

There are four sites in Bolivia known for Late Cretaceous dinosaur trackways , all dated to Campanian - Maastrichtian. Toro-Toro is the most northerly located of these sites. The first trackways were described in 1968, and 2,500 tracks have been recorded since. The footprints represent entire dinosaur faunas, with sauropods, ankylosaurs, hadrosaurs and raptors.  A sedimentological stud shows that the lithology mainly comprises coarse-grained sandstones and limestone with a relatively high clay content. Some beds host stromatolites, ooids and  evaporates but the successions are devoid of palynomorphs. A palynological study from coeval deposits in the north western part of the country, however, reveals a diverse and rich vegetation (Vajda, 1999). Angiosperm pollen dominate heavily,  mainly comprised by small monocolpate, tricolpate and tricolporate grains, generally with a finely reticulate exine, but psilate and striate forms are also recognized. Interestingly spore masses belonging to the water fern Azolla are abundant in a few beds (Vajda & McLoughlin, 2005) .Key taxa include Crassitricolporites brasiliensis,  Proteacidites dehanii, Tricornites elongatus and species belonging to Aquilapollenites.

Vajda, V., 1999. Miospores from Upper Cretaceous–Paleocene strata in northwestern Bolivia. Palynology 23, 183–198.

Vajda, V. & McLoughlin, S. 2005. A new Maastrichtian-Paleocene Azolla species from Bolivia, with a comparison of the global record of coeval Azolla microfossils. Alcheringa 29, 305-329.

A small-scale study of sampling bias: the Chalk of Hampshire, UK

^*Fiona M Walker¹

¹University of Bristol

The fossil record captures past biodiversity imperfectly. Does sampling bias obscure biological diversity signals in palaeontological richness data? Global studies find a correlation between sampling proxies and sampled fossil diversity. However, regional studies find that this relationship breaks down on small scales, or that the strength of this relationship depends on the taxon, tectonic and depositional setting and rock exposure. The relationship between global (gamma) and local (alpha) diversity measures is of course modified by inter-regional differentiation (beta diversity), but comparisons across scales are intriguing. A newly-compiled dataset of fossil occurrences from the Chalk of Hampshire, UK, is presented. Analysis of diversity in this succession per formation and per map square reveals a correlation between diversity and sampling effort measured at this scale. Genus richness counts are driven by sampling bias in this dataset, but this masks real local faunal turnover as demonstrated by the episodic nature of species distributions in the Chalk and similarity indices for each formation. Historic exposure will be quantified using maps from the early 1900s, when these fossils were collected, and this will be compared with modern maps and satellite imagery to examine how exposure area has changed over the time palaeontologists have been sampling.

Changing morphospace occupation of the Ammonoidea from the Devonian to the Jurassic

^*Sonny A Walton¹ and Dieter Korn¹

¹Museum fuer Naturkunde, Berlin

Measurements taken from over 5900 ammonoid species were used to calculate three cardinal conch parameters, the conch width index (CWI), umbilical width index (UWI) and the whorl expansion rate (WER). These three parameters are very descriptive in terms of the conch morphology of an ammonoid the CWI affects the hydrodynamic properties of the conch, the UWI the shape of the whorl cross section and the WER the length of the body chamber and the degree of coiling of the conch. A principal components analysis was performed on the conch parameters of all of the ammonoids and a 2-dimensional empirical morphospace was plotted based on the first two principal components.

The PCA was broken down into the 5 major geological periods. The morphospace analysis reveals some interesting changes to the ammonoid conch morphs over time. The morphological range quickly fills out in the Devonian, the Carboniferous is heavily represented by globular conch morphs and despite the Permian-Triassic mass extinction event there is a strong recovery and repopulation of the morphospace. The Jurassic shows a particularly interesting trend as there is a strong reduction in the globular conch morphs leaving a morphospace heavily populated by serpenticonic and lenticular conch morphs.

The first holomorphic fossil chimaeroid fish (Chondrichthyes, Holocephali) from the Mesozoic of Africa

David J. Ward¹, Emma L. Bernard¹, Martha Richter¹ and Evgeny V. Popov²

¹NHM UK
²Saratov State University, Russia.

In February 2014, at the Arizona Mineral and Fossil Show at Tucson, USA, the Natural History Museum, London purchased a slab of dark grey mudstone containing an impression of a chimaeroid fish. Following discussions with academics, commercial collectors and fossil dealers, the consensus was that the specimen could have come from one of the old Jebel Tselfat localities, most likely Aïn el Kerma, to the west of Fez.

With the kind assistance of Professor Driss Ouarhache, Faculty of Science, University of Fez, DJW visited Jebel Tselfat and located the Ain el Kerma excavation in the side of a badland erosion gulley. The sediment, a weathered black organic-rich shale, closely matched the specimen and incidentally yielded a couple of impressions of bony fish skulls

The fish is most probably Elasmodectes willetii, only known from the English Cenomanian chalk.

Mesozoic holomorphic chimaeroids are an extremely rare occurrence in the fossil record and are only known from the Late Jurassic of southern Germany (Solenhofen, Eichstätt), from the Late Cretaceous (Cenomanian) of Lewes England and the Lebanese Chalk (Santonian). This is the first documented example of a holomorphic fossil chimaeroid fish, of any age, from the continent of Africa.

Recovery from the K-Pg mass extinction in Antarctica

Rowan J. Whittle¹, James D. Witts², Vanessa Bowman¹, Jon Ineson³, Jane E. Francis¹ and J. Alistair Crame¹

¹British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET
²School of Earth and Environment, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT
³Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350, Copenhagen, Denmark

The modern Antarctic marine fauna arose following the Cretaceous-Paleogene (K-Pg) mass extinction event, and biotic recovery occurred throughout the Cenozoic Era. New stratigraphic analysis linked with comprehensive fossil collections from Seymour Island, located on the Antarctic Peninsula (65°S), has enabled the detailed study of this critical time interval. This locality comprises one of the best exposed and most complete high latitude Cretaceous–Eocene sedimentary sequences anywhere in the world. The K-Pg boundary occurs between Units 9 and 10 of the López de Bertodano Formation, which were deposited in a mud dominated mid-shelf environment.

A bed of disarticulated fish material occurs immediately above the K-Pg boundary suggesting the presence of unstable environmental conditions. The early Paleocene fauna was dominated by infaunal mollusc taxa; two deposit feeding bivalves, three suspension feeding bivalves, one deposit feeding gastropod and one predatory gastropod. A radiation of new molluscan taxa began around 0.5 million years after the K-Pg event close to the contact between the López de Bertodano and Sobral formations. Infaunal and epifaunal carnivorous neogastropods became more prominent at this level. Overall, the fossil community of the lower to middle Sobral Formation was dominated by molluscs living in a shallow water deltaic environment.

The palynology of the Bajocian of Swabia, south west Germany: A rapid dinoflagellate cyst radiation during the Middle Jurassic

^*Nickolas J. Wiggan¹, James B. Riding² and Matthias Franz³

¹Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
²British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK
³Regierungsprasidium Freiburg– Dept. 9, State Authority for Geology, Mineral Resources and Mining, Albertstraße 5, Freiburg D-79104, Germany

During the Bajocian (Middle Jurassic, 170.3–168.3 Ma), the dinoflagellates underwent an explosive radiation, resulting in ~50 dinoflagellate cyst species (mainly of family Gonyaulacaceae) appearing by the end of this interval. This is broadly coincident with diversification within coccolithophores, and the appearance of the first planktonic foraminifera; indicating that major evolutionary changes in plankton occurred at this time.

Material has been collected and analysed from Swabia, south-west Germany; in this region the Bajocian is expanded and largely complete. Diversity increases dramatically through the stage and considerable morphological changes in archaeopyle (excystment aperture) formation occurs. Assemblages from the Lower Bajocian are of low diversity, being dominated by Dissiliodinium giganteum, the first dinocyst to shed multiple precingular plates during excystment. A rapid increase in diversity occurs in the ‘middle’ Bajocian, with ~20 first occurrences, including that of Acanthaulax crispa, the first gonyaulacoid dinocyst to evolve a one plate precingular archaeopyle. This would become one of the main excystment modes in gonyaulacoids, and remains so to the Recent. Diversity increases throughout the Upper Bajocian with the emergence of several species of Ctenidodinium; this represents the development of epicystal archaeopyles, which would become a prominent excystment mode for the rest of the Middle Jurassic.

Sternal morphology and soaring flight

^*Megan E Williams¹

¹University of Cambridge

The sternum is the origin of major flight muscles in birds; both of the down stroke and upstroke. Morphological aspects, such as carina reduction, have been associated with flight loss. This study investigates the association of sternal morphology with soaring flight (where lift energy is gained from atmospheric movements rather than flapping). I focused on dynamic (energy from wind shear) and static (energy from thermals) soaring as these make little use of flapping flight.

Traditional and geometric morphometric techniques were used to examine sterna. These were sampled from adult specimens of static soaring, dynamic soaring and non-passerine neoavian flapping/flap-gliding species.

Sternal morphology differed significantly with flight style, both with traditional and geometric morphometrics. PCA performed on the geometric data demonstrated that different flight styles occupied distinct areas of morphospace, with dynamic and static soaring birds clearly separated.

Assignment tests displayed high accuracy, with higher accuracy achieved using geometric morphometric techniques. However, in the geometric study, assignment accuracy was greatly reduced when allometry was accounted for, despite accounting for <10% of morphological variation.

These results indicate that the sternum has an important role in flight style and will allow the subsequent identification of potential soaring birds in the fossil record.

Exploring Phosphatization Biases: Evidence from Lebanese fossil Polychaetes

^*Paul Wilson¹, Luke Parry¹ and Jakob Vinther¹

¹Life Science Building, Tyndall Avenue, Clifton, Bristol

The preservation of soft-tissues is rare within the fossil record but, where preserved, yield unprecedented insights. Among the processes responsible for the permineralization of labile tissues, phosphatization is key, often replicating muscle tissue and digestive tracts in three-dimensional calcium phosphates. While efforts have elucidated the broad triggers of this process, understanding of the fine scale geochemical controls that drive phosphatization is poor, due to the limited extent of such tissue permineralization. However, the discovery of polychaetes showing full-body phosphatization from the Cretaceous Lebanese Lagerstaetten of Hakel and Hjoula allows an oppurtunity to explore this territory and elucidate the triggers responsible for extensive phosphatization, particularly as other polychaetes in these beds rarely show mineralization. Analysis via myoanatomical mapping, SEM and comparison to extant CT-scanned polychaetes reveals that these fossils belong to a single taxon in the Amphinomidae, revealing three prominent biases in the process of phosphatization: 1) a taxon bias, where extensive phosphatization is limited to a single polychaete taxon 2) a tissue bias, where different tissues within a fossil have varying fidelities and 3) a locational bias, where fidelity varies along the body. However, ready explanations for these biases are lacking, highlighting a need for more experimental data on phosphatization.

Late Jurassic to Early Cretaceous Dinoflagellate Cysts from the Eastern Gulf of Mexico: Facilitating future exploration and development 

^*Stephanie Wood¹, Charles Wellman¹, Katrin Ruckwied² and Iain Prince²

¹University of Sheffield
²Shell Exploration and Production, USA

The Late Jurassic to Early Cretaceous deposits of the Eastern Gulf of Mexico (EGoM) are one of the world’s major hydrocarbon reserves. However, the Gulf of Mexico is a structurally complex area in terms of its tectonic setting. This unusual basin therefore requires establishment of a high resolution biostratigraphy to facilitate correlation and aid understanding of its sedimentary fill. Unfortunately there is a distinct lack of published studies on dinoflagellate cysts from these strata. This research project aims to fill that data gap by producing a high resolution dinoflagellate cyst biostratigraphy from data collected from three wells around the EGoM. 175 samples have been processed and analysed using light microscopy. Rich assemblages of well preserved palynomorphs, dominated by dinoflagellate cysts, have been recovered. These have been systematically described and quantitative occurrence/abundance data have been collected and analysed using the data storage and analysis packages PAST and STRATABUGS. These data have been utilised in a detailed analysis of the biostratigraphy, palaeoecology, palaeoenvironments and palaeogeography of the deposits and in developing a robust high-resolution biostratigraphy. This will greatly facilitate upcoming exploration and development activities in this basin and ensure future energy security.