The first protorosaur from the Middle Triassic of China, Dinocephalosaurus orientalis Li is known from two specimens: the holotype (an isolated skull in association with the first three cervical vertebrae), and a referred specimen (an almost complete, associated and partially articulated specimen lacking the tail). This material is here described in detail. A complete and amended diagnosis is given for the genus an ... Read more »

A bone recovered from the Upper Cretaceous Maungataniwha Sandstone of North Island, New Zealand, appears to be an incomplete titanosaurian caudal centrum. The proportions of the apparently procoelous centrum suggest that it is a middle caudal. This indicates the presence of a titanosaurian sauropod in Campanian-Maastrichtian New Zealand. At this time, titanosaurians are known from South America, Africa, India, Laur ... Read more »

Several hundred disarticulated dinosaur bones have been recovered from a large quarry at Wulaga (Heilongjiang Province, China), in the Upper Cretaceous (Maastrichtian) Yuliangze Formation. The Wulaga quarry can be regarded as a monodominant bonebed: more than 80% of the bones belong to a new lambeosaurine hadrosaurid, Sahaliyania elunchunorum gen. et sp. nov. This taxon is characterised by long and slender paroccip ... Read more »

Recent discoveries and analyses have drawn increased attention to Ceratosauria, a taxonomically and morphologically diverse group of basal theropods. By the time of its first appearance in the Late Jurassic, the group was probably globally distributed. This pattern eventually gave way to a primarily Gondwanan distribution by the Late Cretaceous. Ceratosaurs are one of several focal groups for studies of Cretaceous ... Read more »

The “ethmoid complex” is an enigmatic element of the anterior portion of the braincase first described in Tyrannosaurus rex in 1912, which has since been recognized in many non-avian theropods. Because the “ethmoid complex” is a landmark for the reconstruction of the olfactory apparatus of non-avian theropods, we clarify the homology of this structure among archosaurs. The “ethmoid complex” consists of a trough-sha ... Read more »

A new eusuchian skull from the Maastrichtian locality of Oarda de Jos in the southwestern Transylvanian Basin of Romania represents the best-preserved known specimen of Allodaposuchus precedens Nopcsa, 1928. This new fossil allows us to clearly characterize the skull morphology of A. precedens and to reject the idea, as recently suggested, that the taxon could be considered a nomen dubium. Parsimony analysis confir ... Read more »

Madagascar has a diverse but mainly endemic frog fauna, the biogeographic history of which has generated intense debate, fueled by recent molecular phylogenetic analyses and the near absence of a fossil record. Here, we describe a recently discovered Late Cretaceous anuran that differs strikingly in size and morphology from extant Malagasy taxa and is unrelated either to them or to the predicted occupants of the Ma ... Read more »

A new Late Cretaceous titanosaur sauropod from the Bauru Basin of Brazil, Uberabatitan ribeiroi gen. et sp. nov., represented by at least three specimens, is described. The material comes from a level of coarse sandstone within the Serra da Galga sequence in Uberaba County, Minas Gerais State. The fossiliferous strata belong to the Marı´lia Formation (Serra da Galga Member), Bauru Group, considered to be Maastricht ... Read more »

Only two ornithomimid genera, Ornithomimus and Struthiomimus, are currently known from the Upper Cretaceous of North America. However, a number of ornithomimid elements from Alberta’s Dinosaur Park Formation (Upper Campanian), cannot be assigned to either Ornithomimus or Struthiomimus. These bones, including a frontal, caudal vertebrae, and unguals of the manus and the pes, come from animals significantly larger th ... Read more »

The Kuehneosauridae (Late Triassic, Britain, USA) had remarkable adaptations, most notably their elongate mid-dorsal ribs that were presumably covered with a skin membrane in life. These lateral ‘wings’ have always been linked with some form of gliding adaptation, but quantitative studies have been limited. Here, we provide a thorough aerodynamic analysis of both genera of British kuehneosaurids based on theory and ... Read more »

A phylogenetic analysis of reproductive and oological (egg) traits of theropod taxa allows determination of the sequence in which these traits evolved in Theropoda. Our results indicate that several avian reproductive traits, such as adults sitting on eggs, asymmetrical eggs, unornamented eggshell surface, and complex eggshell ultrastructure,were already present in non-avian maniraptorans, and could have evolved in ... Read more »

The oldest records of mammal-like therapsids in Laurasia are from the Ocher Complex of Russia and the Xidagou Formation of China, whereas in Gondwana they are restricted to the Eodicynodon Assemblage Zone, Beaufort Group of the South African Karoo. This fauna, which is relatively depauperate when compared with younger assemblage zones from the Karoo, shows an amazing diversity of therapsids including: dinocephalian ... Read more »

Light Detection And Range (LiDAR) imaging provides a means to model the 3D geometry of fossil tracks in the field with high accuracy. This represents a considerable advance for the science of vertebrate ichnology in which traditional field methods suffer from a significant degree of abstraction and lack the resolution required to interpret tracks quantitatively. Three-dimensional LiDAR models provide additional mor ... Read more »

A new alvarezsaur, Albertonykus borealis, is described from the Lower Maastrichtian of the Horseshoe Canyon Formation, Alberta, Canada. Forelimb and hindlimb elements from at least two individuals were recovered from the Albertosaurus bonebed at Dry Island Provincial Park, along with pedal phalanges from nearby localities. Phylogenetic analysis shows that Albertonykus is the sister taxon of the Asian clade Mononyki ... Read more »

We report on a new Early Cretaceous bird from China that sheds significant light on the evolutionary transition between primitive birds with a long bony tail and those with a short tail ending in a pygostyle. A cladistic analysis of basal birds supports the placement of the new fossil as the sister-taxon of all pygostylians. Possessing a unique hand morphology with a phalangeal formula of 2-3-3-x-x and a reduced nu ... Read more »

A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is
erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is characterized by absence of pleurocoels in dorsal vertebrae and the dorsal verterbrae with slightly convex anterior articular surfaces, moderately concave posterior articular surfaces; the fourth troch ... Read more »

A new species, Camptosaurus aphanoecetes, is named for a partial skeleton of ornithopod dinosaur from the Morrison Formation (Upper Jurassic) of Dinosaur National Monument, Utah. The specimen was originally described as Camptosaurus medius Marsh, 1894, and later referred to Camptosaurus dispar (Marsh, 1879). Comparison of the specimen with a large sample of C. dispar from Quarry 13 shows differences in the proporti ... Read more »

The largest known flying organisms are the azhdarchid pterosaurs, a pterodactyloid clade previously diagnosed by the characters of their extremely elongate middle- series cervical vertebrae. The named species of the Azhdarchidae are from the Late Cretaceous. However, isolated mid-cervical vertebrae with similar dimensions and characters have been referred to this group that date back to the Late Jurassic, implying ... Read more »

Newly prepared material of Keichousaurus hui demonstrates that the nasals are very reduced and do not contribute to the margins of external nares, the quadrate lacks a posterior condylar process, the premaxilla and anterior dentary teeth are enlarged and procumbent, the maxilla has a pair of ‘canines,’ the vomers are co-ossified, the suborbital
fenestrae are very reduced or lost, a distinct coronoid process is p ... Read more »

Exceptionally large teeth attributable to the theropod genus Troodon are abundant in Upper Cretaceous rocks (Campanian–Maastrichtian) of northern Alaska. The dominance of low-angle light in this Cretaceous high-latitude environment seems to have selected for an abundance of Troodon. The population of these Alaskan specimens— morphologically the same as teeth attributable to this taxon in other regions—show a mean a ... Read more »