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A fertile marattialean fern from the Lower Shihhotse Formation, Lower Permian of Taiyuan, north China is ascribed to a new genus, Taiyuanitheca, as T. tetralinea sp. nov. The fronds are Pecopteris-like with two rows of synangia arranged on each side of the midvein on the adaxial surface of the pinnules. The synangia are sessile and ring-like with elliptical sporangia that are fused together along their full length. The new fern is compared with fossil and extant marattialeans and new evolutionary pathways are proposed for this group of plants.

• Read more about A new fern from the Lower Permian of China and its bearing on the evolution of the marattialeans

The Maastrichtian of southern Sweden has yielded more than 2000 teeth of squaloid sharks. Seven species have been identified: Microetmopterus wardi gen. et sp. nov., Proetmopterus hemmooriensis gen. nov., Eoetmopteris cf. E. supracretaceous, Centroscymnus schmidi, Squalus ballingsloevensis sp. nov., S. balsvikensis sp. nov. and S. gabrielsoni sp. nov, Etmopterine sharks, now restricted to the cold bottom-waters of the outer continental and insular shelves and slopes, apparently thrived in the shallow coastal waters of the Kristianstad Basin during the earliest Maastrichtian.

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In a revised diagnosis, Orthambonites is restricted to a small group of late lower Ordovician (latest Arenig-Llanvirn equivalent) brachiopods from Baltoscandia. Orthambonites rotunda is proposed as the formal type species of the genus to replace Orthambonites transversa which is considered a nomen dubium. Revision of Orthis calligramma suggests in turn that it is a senior subjective synonym of O. rotunda, and thus becomes the effective type species of Orthambonites.

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The motion at the shoulder joint of the Cretaceous pterodactyloid pterosaur Santanadactylus brasilensis is investigated. Shoulder movement is important because it determines the orientation and amplitude of the wing stroke during flapping flight. In previously studied pterosaurs, the principal shoulder motion is in the transverse vertical plane with, in at least one species, a degree of rotation about an axis along the length of the wing.

• Read more about An unusual flight mechanism in the Pterosauria

A shale sample from the Black Shale Member of the c. 1250 Ma Agu Bay Formation, Fury and Hecla Group, north-west Baffin Island contains abundant, well-preserved microfossils. The assemblage is dominated by small leiosphaerid acritarchs of which c. 15 per cent show structures here interpreted as medial split release structures. Colonial unicells and larger spheroidal acritarchs are uncommon, and filamentous microfossils extremely rare.

• Read more about Palaeoenvironmental distribution of Proterozoic microfossils, with an example from the Agu Bay Formation, Baffin Island

In a sectorial-expansion analysis the shell can be described as a series of independent helicospirals joining homologous points on the shell's surface. In actual shells, these helicospirals are longitudinal ornaments. Therefore, the aperture is considered as a set of points, obtained at its intersection with these ornaments. Any apertural segment (between two consecutive points) is potentially able to expand or contract independently during growth. With the aim of quantifying this change in length in any coiled shell, a differential parameter (Sc) has been devised.

• Read more about Sectorial-expansion analysis of irregularity coiled shells; application to the Recent gastropod Distorsio

Exceptional soft-part preservation of the internal anatomy of beetles (Nitidulidae and Cantharidae) is described from Tertiary amber, for the first time from the Dominican Republic. A variety of tissues is preserved, including elements of the nervous, digestive, respiratory, locomotory and sensory systems.

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Some phosphatized soft tissues of vertebrates and invertebrates from the Santana Formation (Cretaceous) of Brazil are too delicate to withstand acid preparation despite their relative insolubility. Examination of sectioned specimens using energy dispersive analytical systems attached to scanning electron microscopes provides an alternative method. This allows the nature of such delicate fossil soft tissues to be seen for the first time, and the relationship of fossil soft tissues to skeletal elements, to other diagenetic mineral phases and to sedimentary structures to be examined.

• Read more about Elemental mapping: a technique for investigating delicate phosphatized fossil soft tissues

Archaeopteridium tschermakii (Stur) Kidston is described from compressions and fusainized material from the Puddlebrook locality of the Drybrook Sandstone of Gloucestershire. Fronds are up to 400 mm long and bifurcate, bearing oval to rounded pinnules on pinnae varying in complexity according to their position on the frond. Pinnules have a prominent surface pattern with several veinlets entering the pinnule base which divide and extend to the pinnule margin.

• Read more about The gymnosperm Archaeopteridium tschermakii and an associated glandular fructification from the Upper Visean Drybrook Sandstone of Great Britain

Concornis lacustris gen. et sp. nov. is a new fossil bird from the Early Cretaceous (Barremian) of Las Hoyas, Cuenca, Spain. Concornis is roughly twice the size of Iberomesornis, the first bird described from Las Hoyas, but it is not the adult of the latter. Concornis is more derived than Iberomesornis, with a true tibiotarsus and a fan-like distal metatarsal zone with distinct trochlear structures. Only the proximal metatarsal region is fused. The sternum has a slight but conspicuous posterior median keel. The phalangeal structure of the manus is like that of extant birds.

• Read more about A new bird from the Early Cretaceous of Las Hoyas, Spain, and the early radiation of birds