Archive

This study involves bryophyte fossils from the Teresina Formation (Permian–Guadalupian) collected in the Rio Preto Quarry in the state of Paraná, southern Brazil. Two new genera are proposed, with two new species: Capimirinus riopretensis sp. nov. and Yguajemanus yucapirus sp. nov. C. riopretensis sp. nov. included a lateral sporophyte that was organically attached to a gametophyte and is thus one of the oldest pleurocarpous fossils known today.

• Read more about Permian bryophytes of Western Gondwanaland from the Paraná Basin in Brazil

The last one million years are important in terms of climate development during the so-called Mid-Pleistocene Transition when amplification of the glacial–interglacial cycles occurred. This study describes abundance changes in fossil planktonic foraminifera in sediments from Core T89-40, retrieved from the Walvis Ridge in the south-east Atlantic, across this time period. Cycles between upwelling and subtropical planktonic foraminiferal assemblages are shown to mirror changes between glacial and interglacial periods, respectively.

• Read more about Sensitivity of south-east Atlantic planktonic foraminifera to mid-Pleistocene climate change

The bioclaustration of the pyrgomatid barnacle Ceratoconcha aff. costata within the carbonate skeleton of a colonial hermatypical coral (Tarbellastrea reussiana) is described from a middle Miocene basaltic rocky palaeoshore on a small north-eastern Atlantic islet of Porto Santo (Madeira Archipelago, Portugal). The resulting structure is named as a new trace fossil Imbutichnus igen. nov., characterized by a small, funnel-like cavity, a circular to oval cross-section, with a nearly cylindrical shape in the upper part and a conical shape towards the base. Imbutichnus costatum isp. nov.

• Read more about Symbiotic association of a pyrgomatid barnacle with a coral from a volcanic middle Miocene shoreline (Porto Santo, Madeira Archipelago, Portugal)

Chigutisauridae is the longest-lived trematosaurian clade (from early Triassic to early Cretaceous). They were reported in Argentina, Australia, India and South Africa. This contribution reports a putative chigutisaurid specimen in the Carnian of southern Brazil (Santa Maria Formation, Paraná Basin). The material comprises two skull fragments, a mandibular fragment, a clavicular blade and a humerus. Ontogenetic features point to an early development stage of the specimen.

• Read more about The presence of Compsocerops (Brachyopoidea: Chigutisauridae) (Late Triassic) in southern Brazil with comments on chigutisaurid palaeobiogeography

The dinosaur Stegosaurus is characterized by osteoderms of alternating plates and terminal paired spikes. Previous studies have described the histological features and possible functions of these osteoderms. However, ontogenetic changes are poorly documented. In this study, the ontogenetic changes of the osteoderms are examined using eight different ontogenetic skeletons (a juvenile, a subadult, a young adult, and five old adults based on the cortical histology of their body skeletons). The juvenile plate and subadult spike show thin cortex and thick cancellous bone.

• Read more about Ontogenetic histology of Stegosaurus plates and spikes

Two new species of Orchestina (Araneae: Oonopidae) are described as O. gappi sp. nov. and O. rabagensis sp. nov. from the Cretaceous of France and Spain, respectively. Two additional specimens from Spain are placed within Orchestina but not assigned to species. These formal descriptions are the oldest for the genus and the family Oonopidae. The discovery of these older Orchestina is not surprising, as the genus is considered a basal member of the Oonopidae and one of the most diverse and long-lived spider lineages.

• Read more about New Orchestina Simon, 1882 (Araneae: Oonopidae) from Cretaceous ambers of Spain and France: first spiders described using phase-contrast X-ray synchrotron microtomography

New dinosaur tracksites are described from the Bajocian–Bathonian Bemaraha Formation of western Madagascar. Two track-bearing surfaces can be followed over a distance of at least 4 km, suggesting the existence of a hitherto unrecognized megatracksite. The track assemblage is theropod dominated, but sauropod tracks also occur at one site. Qualitative and quantitative analysis of the abundant theropod track material suggests that most, if not all, theropod footprints are attributable to a single trackmaker and are referred to Kayentapus isp.

• Read more about New dinosaur tracksites from the Middle Jurassic of Madagascar: ichnotaxonomical, behavioural and palaeoenvironmental implications

Directed evolution of life through millions of years, such as increasing adult body size, is one of the most intriguing patterns displayed by fossil lineages. Processes and causes of such evolutionary trends are still poorly understood. Ammonoids (externally shelled marine cephalopods) are well known to have experienced repetitive morphological evolutionary trends of their adult size, shell geometry and ornamentation. This study analyses the evolutionary trends of the family Acrochordiceratidae Arthaber, 1911 from the Early to Middle Triassic (251–228 Ma).

• Read more about Large-scale evolutionary trends of Acrochordiceratidae Arthaber, 1911 (Ammonoidea, Middle Triassic) and Cope’s rule

A new genus and species of Devonian tetrapod has been identified from material collected in 1947 from the southern slope of Mt. Celsius, Ymer Ø, North-East Greenland. The specimen preserves both lower jaws, partial palate, premaxillae and maxillae, with a natural mould of parts of the shoulder girdle. The new taxon, Ymeria denticulata, shows differences in dentition, skull ornament and lateral line expression from both Acanthostega and Ichthyostega, but it shows a closer resemblance to the latter.

• Read more about A new genus of Devonian tetrapod from North-East Greenland, with new information on the lower jaw of Ichthyostega

A new species of the Late Devonian lungfish Rhinodipterus is described from the Frasnian Gogo Formation, northern Western Australia. The description is based on a single specimen preserved in a small concretion, represented by elements of the skull roof, lower jaw, palate, neurocranium, hyoid arch, pectoral girdle and other parts of the postcranial skeleton. Rhinodipterus kimberleyensis sp. nov. differs from other species in the shape of its parasphenoid, number of tooth rows, nature of the tooth plates and characteristics of the skull roof.

• Read more about A new species of long-snouted lungfish from the Late Devonian of Australia, and its functional and biogeographical implications