Compared with other Mesozoic tetrapod groups, chigutisaurid fossils from Australia are rare, only three named taxa described the continent. From Queensland, Keratobrachyops australis is known Triassic, and Siderops kehli Jurassic. Koolasuchus cleelandi, Cretaceous of Victoria, represents youngest-known temnospondyl globally. Here we describe first New South Wales, Early–Middle Triassic Terrigal...

Turtles have been known since the Upper Triassic (210Myr old); however, fossils recording the first steps of turtle evolution are scarce and often fragmentary. As a consequence, one of the main questions is whether living turtles (Testudines) originated during the Late Triassic (210Myr old) or during the Middle to Late Jurassic (ca 160Myr old). The discovery of the new fossil turtle, Condorchel...

Studies of the end-Permian mass extinction have emphasized potential abiotic causes and their direct biotic effects. Less attention has been devoted to secondary extinctions resulting from ecological crises and the effect of community structure on such extinctions. Here we use a trophic network model that combines topological and dynamic approaches to simulate disruptions of primary productivit...

Sphenodontians were a successful group of rhynchocephalian reptiles that dominated the fossil record of Lepidosauria during the Triassic and Jurassic. Although evidence of extinction is seen at the end of the Laurasian Early Cretaceous, they appeared to remain numerically abundant in South America until the end of the period. Most of the known Late Cretaceous record in South America is composed...

Crittenden Springs in northeastern Nevada yields M. gracilitatis Zone ammonoids renowned for the finely detailed, exquisite preservation of the test, which sometimes even displays relict color patterns. Evidence reveals most of the fossiliferous Lower Triassic beds in the Crittenden Springs area are overturned and this conclusion places the Meekoceras gracilitatis Zone portion of the section an...

Sauropodomorph dinosaurs originated in the Southern Hemisphere in the Middle or Late Triassic and are commonly portrayed as spreading rapidly to all corners of Pangaea as part of a uniform Late Triassic to Early Jurassic cosmopolitan dinosaur fauna. Under this model, dispersal allegedly inhibited dinosaurian diversification, while vicariance and local extinction enhanced it. However, apomorphy-...

The Alpine Haselgebirge Formation represents an Upper Permian to Lower Triassic evaporitic rift succession of the Northern Calcareous Alps (Eastern Alps). Although the rocksalt body deposits are highly tectonised, consisting mainly of protocataclasites and mylonites of halite and mudrock, the early diagenetic history can be established from non-tectonised mudrock bodies: Cm-sized euhedral halit...

Birds, dinosaurs, crocodilians, pterosaurs and their close relatives form the highly diverse clade Archosauriformes. Archosauriforms have a deep evolutionary history, originating in the late Permian, prior to the end-Permian mass extinction, and radiating in the Triassic to dominate Mesozoic ecosystems. However, the origins of this clade and its extraordinarily successful body plan remain obscu...

New Mexico Museum of Natural History and Science (NMMNH) locality L-3845 in the Petrified Forest Formation of the Chinle Group (Rio Arriba County, NM) yields nonmarine fossil vertebrates, invertebrates, and plants of Revueltian (early-mid Norian, ~218-210 Ma) age. We describe a 48 mm long by 19 mm wide decapod specimen (NMMNH P-29041) that originated in one of several fining-upward depositional...