Ornithischian dinosaurs are one of the most taxonomically diverse dinosaur clades during the Mesozoic, yet their origin and early diversification remain virtually unknown. In recent years, several new Triassic ornithischian taxa have been proposed, mostly based upon isolated teeth. New discoveries of skeletal material of some of these tooth taxa indicate that these teeth can no longer be assign...

Previous studies have suggested a variety of causes for the end-Permian extinction event including a bolide impact, flood basalt volcanism, methane clathrate dissociation, or some combination of catastrophic processes. One common feature of these hypotheses is the prediction of an enhanced earliest Triassic greenhouse. New high-resolution geochemical results from Graphite Peak, Antarctica suppo...

Triassic vertebrate tracks are known from the beginning of the 19th century and have a worldwide distribution. Several Triassic track ichnoassemblages and ichnotaxa have a restricted stratigraphic range and are useful in biochronology and biostratigraphy. The record of Triassic tracks in the Iberian Peninsula has gone almost unnoticed although more than 25 localities have been described since 1...

Abstract Sections at Baghuk Mountain, 45 km NNW of Abadeh (Central Iran), have excellent exposures fossiliferous marine Late Permian to Early Triassic sedimentary successions. Detailed bed-by-bed sampling enables the analysis microfacies changes three successive rock units across Permian–Triassic boundary. The Hambast Formation is mainly result biogenic carbonate production. Its dominated by bi...

Dinosaurs Linked to an Iridium Anomaly at the Triassic-Jurassic Boundary” Olsen et al. (1), in a detailed study of skeletal remains and fossil footprints in the Newark Supergroup of eastern North America, found that Triassic theropods there were all of small to moderate size, whereas large theropod bones and footprints such as Eubrontes giganteus ( 35 cm long) did not appear until the earliest ...

Abstract This paper presents organic geochemical evidence pointing to the occurrence of wildfire events at Triassic–Jurassic boundary in Central Iran. The studied outcrop section (the Kamarmacheh Kuh section) is comprised Upper Triassic Nayband Formation which passes conformably into Lower Jurassic Ab-e-Haji with no sharp boundary. Organic petrographical studies reveal a higher concentration se...

The rise of archosaurs during the Triassic and Early Jurassic has been treated as a classic example of an evolutionary radiation in the fossil record. This paper reviews published studies and provides new data on archosaur lineage origination, diversity and lineage evolution, morphological disparity, rates of morphological character change, and faunal abundance during the Triassic–Early Jurassi...