Archive

We describe a weakly biomineralized non-trilobite artiopodan arthropod from the Guzhangian Weeks Formation of Utah. Falcatamacaris bellua gen. et sp. nov. is typified by a thin calcitic cuticle, broad cephalon without eyes or dorsal ecdysial sutures, an elongate trunk with distinctively sickle-shaped pleural spines and a long tailspine with a bifurcate termination. The precise affinities of Falcatamacaris gen. nov. are problematic due to the presence of unique features within Artiopoda, such as the peculiar morphology of the pleural and posterior regions of the trunk.

• Read more about A rare non-trilobite artiopodan from the Guzhangian (Cambrian Series 3) Weeks Formation Konservat-Lagerstätte in Utah, USA

Despite the extensive fossil record of higher crabs (Eubrachyura) from Late Cretaceous and Cenozoic rocks worldwide, their Early Cretaceous occurrences are scarce and fragmentary, obscuring our understanding of their early evolution. Until now, representatives of only two families of eubrachyuran-like crabs were known from the Early Cretaceous: Componocancridae and Tepexicarcinidae fam. nov., both monospecific lineages from the Albian (~110–100 Ma) of North and Central America, respectively. The discovery of Telamonocarcinus antiquus sp. nov.

• Read more about The oldest higher true crabs (Crustacea: Decapoda: Brachyura): insights from the Early Cretaceous of the Americas

A humerus and a coracoid from the Early Eocene Wasatch Formation in the Washakie Basin of south-western Wyoming are the oldest materials (by ~2 million years) of the pelecaniform Limnofregata (Aves) and represent a new large species, Limnofregata hutchisoni sp. nov. This fossil is the oldest known member of the frigatebird lineage. Other than its large size relative to Limnofregata azygosternon and L. hasegawai, the new material is very similar morphologically to other known Limnofregata specimens.

• Read more about A new species of Limnofregata (Pelecaniformes: Fregatidae) from the Early Eocene Wasatch Formation of Wyoming: implications for palaeoecology and palaeobiology

Regeneration of the calcareous rigiclaudent operculum following severe, non-lethal, predatory attacks is described in two specimens of the characteristic Silurian gastropod Oriostoma from the English Midlands. This is the first record of the regeneration of opercula in Palaeozoic gastropods and of opercula conjoined with shells that have been repaired after significant, failed, durophagous attacks. In one specimen, a series of repaired injuries culminates in a repaired aperture closed by the operculum.

• Read more about Operculum regeneration following failed predation in the Silurian gastropod Oriostoma

Ray-finned fishes (Actinopterygii) constitute approximately half of all living vertebrate species. A stable hypothesis of relationships among major modern lineages has emerged over the past decade, supported by both anatomy and molecules. Diversity is unevenly partitioned across the actinopterygian tree, with most species concentrated within a handful of geologically young (i.e. Cretaceous) teleost clades.

• Read more about The early evolution of ray-finned fishes

Over the last two decades, there has an been increasing interest in applying vibrational spectroscopy in palaeontological research. For example, this chemical analytical technique has been used to elucidate the chemical composition of a wide variety of fossils, including Archaean putative microfossils, stromatolites, chitinozoans, acritarchs, fossil algae, fossil plant cuticles, putative fossil arthropods, conodonts, scolecodonts and dinosaur bones.

• Read more about Vibrational spectroscopy of fossils

Geometric morphometric methods applied to theropod tracks from the Huérteles Formation (Berriasian, Spain) are here shown to be invaluable for drawing comparisons between theropod tracks with different preservation modes (true tracks, shallow undertracks and natural casts) or differing in the preservation of anatomical features (e.g. digital pads). Principal components analysis and thin-plate spline methods can quantitatively distinguish between the broad groups of tracks in a sample and establish the main differences between them.

• Read more about Geometric morphometric analysis applied to theropod tracks from the Lower Cretaceous (Berriasian) of Spain

Here, we describe Sinathyris crassa gen. et sp. nov., a new early Emsian (Early Devonian) athyridide brachiopod with a double spiralium from the Guangxi Province of southern China. Unlike the majority of genera of the subfamily Helenathyridinae, which possess accessory spiral lamellae developed directly from the jugal branches, the form described here shows these lamellae arising from a distally bifurcating jugal stem. These differences suggest that the double spiralium in S. crassa might have appeared independently from the double spiralium of the helenathyridins.

• Read more about Parallel evolution of jugal structures in Devonian athyridide brachiopods

Proterosuchidae is one of the first clades of Archosauriformes (archosaurs and closely related species) to appear in the fossil record, with the richest sample of the group coming from the Lystrosaurus Assemblage Zone (earliest Triassic) of South Africa. Four nominal proterosuchid species were described from South Africa during the twentieth century (Proterosuchus fergusi, Chasmatosaurus vanhoepeni, Chasmatosaurus alexanderi and Elaphrosuchus rubidgei), but interpretations of their taxonomy have been widely disparate.

• Read more about Taxonomy of the proterosuchid archosauriforms (Diapsida: Archosauromorpha) from the earliest Triassic of South Africa, and implications for the early archosauriform radiation

The two olenid species Sphaerophthalmus alatus (Boeck, 1838) and Ctenopyge (Mesoctenopyge) tumida Westergård, 1922, occur together in the Ctenopyge tumida Zone (Zone 19) of the Furongian of Scandinavia. Material from Bornholm, Denmark, forms the basis of this study of the morphology and partial ontogeny of the eyes. The eyes of both species are directed laterally and have virtually panoramic vision, looking out sideways like those of a rabbit. The eye of S.

• Read more about Eyes and vision in the coeval Furongian trilobites Sphaerophthalmus alatus (Boeck, 1938) and Ctenopyge (Mesoctenopyge) tumida Westergård, 1922, from Bornholm, Denmark