Well-preserved cranial remains of a small sphenodontian lepidosaur from the Upper Triassic Caturrita Formation of Rio Grande do Sul, Brazil, are the first record of the genus Clevosaurus Swinton, 1939 from South America. They represent a new species, Clevosaurus brasiliensis, which is distinguished by a very short antorbital region of the skull (corresponding to about 20 per cent of skull lengt...

The Rochechourt impact structure in south-central France, with maximum diameter of 40–50 km, has previously been dated to within 1% uncertainty of the Triassic– Jurassic boundary, at which time ~30% of global genera became extinct. To evaluate the temporal relationship between the impact and the Triassic–Jurassic boundary at high precision, we have re-examined the structure’s age using multicol...

Upper Triassic rocks in northwestern Argentina preserve the most complete record of dinosaurs before their rise to dominance in the Early Jurassic. Here, we describe a previously unidentified basal theropod, reassess its contemporary Eoraptor as a basal sauropodomorph, divide the faunal record of the Ischigualasto Formation with biozones, and bracket the formation with (40)Ar/(39)Ar ages. Some ...

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...

Manuscrito ID: 30163. Recebido em: 19/09/2014. Aprovado em: 19/09/2014. ABSTRACT: New lines of geological evidence strongly suggest that the main period of hydrocarbon maturation within Assistência Formation should be Permian-Triassic, stimulated by a high geothermal gradient that also sustained various manifestations of hydrothermal activity. Three main stages of fluid/hydrocarbon migration ca...

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...

The holotype of Malerisaurus langstoni from the Late Triassic (Otischalkian) Trilophosaurus quarry 2 of West Texas is a chimera. The holotype represents at least 6-7 individuals of four reptilian groups: Trilophosauridae, Rhynchosauridae, Parasuchidae and Aetosauria. The majority of the material, including all of the cranial fragments, are re-identified as Trilophosaurus buettneri. Based on the...

Stratigraphic correlations presented here for the ductilely deformed and metamorphosed rocks exposed in the Shadow Mountains indicate that they formed on the North American continental margin and are not exotic or significantly displaced from their site of origin. These strata represent a depositional history that spans Late Proterozoic and Paleozoic passive margin development, late Paleozoic t...

The tetrapod ichnotaxon Apatopus lineatus is a relatively uncommon component of Late Triassic footprint assemblages. This might be related to the semi-aquatic lifestyle of the trackmakers, which were almost certainly phytosaurs and whose skeletons are known from coeval deposits with a Pangea-wide distribution. Originally described from the Passaic Formation of New Jersey, Apatopus lineatus has ...

Introduction: The age of the ~23 km in diameter Rochechouart impact structure, France, hosted by Precambrian to Paleozoic (Variscan) crystalline rocks of the northwestern French Massif Central, has long time been a matter of debate. Previous studies, including K-Ar, Rb-Sr, apatite and glass fission track, as well as paleomagnetic dating (see [1] for summary of ages), resulted in a broad (Middle...