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A new microchoerine omomyid (Primates, Mammalia) from the English Early Eocene and its palaeobiogeographical implications

A new genus and species of omomyid primate, Melaneremia bryanti, is described from the Early Eocene Blackheath Beds of Abbey Wood, London, UK. It shares unique derived characters with the European subfamily Microchoerinae and is its most primitive member. It is nevertheless more derived than the primitive omomyid Teilhardina belgica from the beginning of the European Eocene. Cladistic analysis shows that the Microchoerinae are sister group to a clade comprising subfamilies Omomyinae and Anaptomorphinae, but excluding Teilhardina belgica and T. asiatica, which are stem omomyids.

Ammonoids and the Triassic/Jurassic boundary in the Himalayas of southern Tibet

The sections of Germig in the Nyalam area, southern Tibet, provide a continuous exposure of ammonoid-bearing, uppermost Triassic and basal Jurassic strata. Eighteen species (three of them new) are described and illustrated: Choristoceras marshi Hauer, C. aff. marshi, C. cf. nobile Mojsisovics, C. nyalamense sp. nov., Eopsiloceras germigense sp. nov., Pleuroacanthites aff. biformis (Sowerby), Rhacophyllites sp., Nevadaphyllites cf. psilomorphus (Neumayr), Neophyllites sp. indet., Neophyllites cf. biptychus (Lange), Psiloceras tibeticum sp. nov., P. calliphyllum (Neumayr), Euphyllites cf.

Reassessment of the genus Leanchoilia (Arthropoda, Arachnomorpha) from the Middle Cambrian Burgess Shale, British Columbia, Canada

The collection, since 1975, of over 1500 specimens of Leanchoilia Walcott by the Royal Ontario Museum has prompted reassessment of the genus and its species from the Middle Cambrian Burgess Shale. Among new characters in Leanchoilia superlata, the type species, are the presence of two pairs of eyes, a dorsal double carina bracketing the axis of the body segments, segmentation of the gill branch of the appendages, and serration along the body edges from the posterior third of the cephalic shield to the last body segment. Leanchoilia persephone Simonetta, previously synonymized with L.

An almost complete juvenile specimen of the cheloniid turtle Ctenochelys stenoporus (Hay, 1905) from the Upper Cretaceous Niobrara Formation of Kansas, USA

A new, unusually well-preserved juvenile specimen of Ctenochelys stenoporus from the Niobrara Formation is described. The skull has come apart at its sutures and all bones of the braincase and ear region are preserved three-dimensionally. This allows a detailed reconstruction of the important brain structures of a basal juvenile cheloniid turtle. It is compared with adult Ctenochelys specimens, and the major ontogenetic changes in the skull and postcranial skeleton are described.

First occurrence of footprints of large therapsids from the Upper Permian of European Russia

Large footprints of terrestrial tetrapods have been found in the Cis-Urals region of European Russia. The footprint horizon is in Late Permian (Changhsingian) deposits of the Vyatkian Gorizont (uppermost Tatarian) approximately 50 m below the local Permian/Triassic boundary. Seventeen randomly orientated footprints were excavated and are referred to the ichnospecies Brontopus giganteus. The footprints were emplaced in a reddish-brown mudstone that was deposited from suspension beneath shallow ponded water in a floodplain environment.

A new temnospondyl from the Permo-Triassic Buena Vista Formation of Uruguay

A partial skull recovered from conglomerates of the Permo-Triassic Buena Vista Formation in Uruguay belongs to a new species, Uruyiella liminea gen. et sp. nov. This species is characterized by a broadly triangular skull with laterally projecting posterior corners, rhytidosteid-like dermal sculpturing, and orbits positioned close to the skull margin.

A new Silurian eurypterid (Arthropoda: Chelicerata) from China

The oldest eurypterid from China is described as Hughmilleria wangi sp. nov., from the Xiaoxiyu Formation (Silurian: latest Llandovery) of Hunan Province. H. wangi is relatively similar to two species from North America, but differs in the development of epimera on the postabdomen, a slightly wider carapace, a styliform telson and the dimensions of the penultimate podomere of the paddle. The Llandovery age of the specimen substantially reduces the ghost range of the genus Hughmilleria.

Redescription of Platycraniellus elegans (Therapsida, Cynodontia) from the Lower Triassic of South Africa, and the cladistic relationships of eutheriodonts

Platycraniellus elegans is an enigmatic Triassic cynodont from South Africa that has only been briefly described previously. New preparation of the holotype and additional unpublished material allows a detailed redescription and comparison with different cynodonts. Platycraniellus elegans is recognized as a valid species of basal cynodont. The distinct suborbital angulation of the zygomatic process, previously considered as a diagnostic character in chiniquodontid cynodonts, and more recently observed in some galesaurids, is also present in P. elegans.

Ammonoids across the Permian/Triassic boundary: a cladistic perspective

The rapid diversification of ceratitid ammonoids during the earliest Mesozoic has been taken at face value as an example of explosive radiation following the Permian/Triassic mass extinction. However, the validity of this interpretation has never been tested within a phylogenetic framework. A total evidence cladistic analysis of Mid-Late Permian and Induan (earliest Triassic) ammonoids confirms the monophyly of the Ceratitida. Partitioned phylogenetic analysis of suture line characters vs.
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