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Linear and concentric markings are described from steinkerns of the Upper Cretaceous ammonite Paravascoceras from Nigeria. The markings are intimately associated with the lobules of the suture lines. They probably record adapical projections of a preseptal prismatic zone of shell material which were secreted by those parts of the mantle corresponding to the lobules during mantle translocation. The posterior mantle margin was under muscular attachment at these points during translocation and subsequent septal secretion.

• Read more about Internal mould markings in a Cretaceous ammonite from Nigeria

A diverse hardground fauna of encrusters, nestlers and borers has been found on calcareous cobbles in the Lower Cretaceous (Upper Aptian) Faringdon Sponge Gravel of south-central England. The bulk of the fauna consists of coelobites that inhabited the vacated borings of bivalves. These coelobites often clustered near the cavity openings, apparently to escape epifaunal predators and physical abrasion, and to avoid sedimentary infilling of the cavity interiors. The few encrusting species common on the outside surfaces are robust and apparently adapted to abrasion resistance.

• Read more about Coelobites and spatial refuges in a Lower Cretaceous cobble-dwelling hardground fauna

Protaspis, meraspis, and holaspis stages of Isotelus giselae sp. nov. from the Edinburg Formation (Middle Ordovician) of Virginia are described; diagnostic features of the dorsal shield are the absence of a distinct lateral depression, and the short, strongly elevated palpebral lobes. Four moults during the protaspis period are denned by changes in the hypostomes. Iotelus spp. A-E, from the lower and upper Lincolnshire, Oranda, and Martinsburg Formations (Middle Ordovician) of Virginia are based on less complete material. Nahannia sp. is described from the Lincolnshire Formation.

• Read more about Silicified trilobites of the family Asaphidae from the Middle Ordovician of Virginia

The necessity of coating fossils with a conductor prior to scanning electron microscopy is avoided using a system in which backscattered electron images are formed of specimens maintained under a relatively low vacuum in an 'environmental chamber'. Resolution and other image characteristics at low magnifications ( < 500 x) generally compare favourably with conventional secondary electron images of coated specimens. Charging artefacts are reduced, edge effect is eliminated, and the backscattered electron image appears flatter than a conventional secondary electron image.

• Read more about Scanning electron microscopy of uncoated fossils

The essential features of the pattern of marine animal diversification in the Phanerozoic are reproduced by a stochastic, quasi-random simulation. The model assumes only (i) random variation in the origination and extinction of lineages and (ii) occurrence of two extraordinary events: 'Late Cambro-Ordovician radiation' and 'Late Permo-Triassic extinction'. It can mimic the shape of the curve of global diversity as well as the pattern of so-called evolutionary faunas.

• Read more about Randomness and diversification in the Phanerozoic: a simulation

Although the Antarctic Peninsula now has a glacial climate, during the Cretaceous and early Tertiary it was sufficiently warm for forests to thrive, even at palaeolatitudes of 59°-62° S. The forests grew on an emergent volcanic arc and the wood was subsequently buried in fluvial and basinal sediments on the margins of the back-arc basin. The forests were composed mainly of podocarp and araucarian conifers. By the late Cretaceous, angiosperm trees were also present, particularly Nothofagus, forming the characteristic forest association of the southern hemisphere today.

• Read more about Growth rings in Cretaceous and Tertiary wood from Antarctica and their palaeoclimatic implications

Restudy of the enigmatic arthropod Necrogammarus salweyi Woodward, hitherto considered to be a crustacean or myriapod, reveals that it is the infracapitulum (fused labrum and palpal coxae) and palp of a large but unspecified pterygotid eurypterid.

• Read more about A new identity for the Silurian arthropod Necrogammarus

Graptolite classification has traditionally been based upon grade groups reflecting general levels of evolutionary complexity. This has been acknowledged as unsatisfactory and the present classification, used widely in the Western world, is a hybrid between this system and what are claimed to be 'natural' groups. A phylogenetic classification, in which taxa are based upon common ancestry, produces a more objective classification with taxa that are diagnosable.

• Read more about A phylogenetic classification of the graptoloids

The anthracosaur amphibian Proterogyrinus pancheni, sp. nov., from localities in the Namurian of the Scottish Carboniferous, is the earliest known member of the Embolomeri to be described from Europe. It closely resembles the North American form P. scheelei, but is distinguished by differences in morphology of the dentition and vertebrae. Functional explanations for the presence of the large Meckelian fenestrae in the embolomere mandible are reconsidered, but it is suggested that they had no specific function and represent incomplete ossification of the mesial surface of the lower jaw.

• Read more about A new anthracosaur amphibian from the Carboniferous of Scotland

Promissum pulchrum Kovacs-Endrody, 1986, originally described as the earliest vascular land plant or an ancestor of the same, is shown to be a conodont. The species is represented by several spectacular bedding plane assemblages which occur in the Soom Shale Member of the Cedarberg Formation, Table Mountain Group, near Clanwilliam, South Africa. Invertebrate fossils from the Soom Shale indicate a late Ashgill (late Rawtheyan to Hirnantian) age. The conodont assemblages are the largest known, reaching 17 mm in length, with individual ramiform elements as long as 14 mm.

• Read more about The first Tertiary sclerosponge from the Americas