The Late Triassic Tetrapod Fauna of the Fleming Fjord Formation, East Greenland

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This project's goal is to provide data critical to understanding vertebrate faunal evolution during the Late Triassic, which includes the origin of mammals as well as other major tetrapod groups (e.g., dinosaurs, turtles, crocodylomorphs, Pterosaurs). Although major originations took place during this time, almost half of known Late Triassic tetrapod families became extinct by the Early Jurassic. The temporal, taxonomic and geographic extent of this faunal turnover has been debated, principally because well-dated, fossiliferous rock sequences are rare. The Late Triassic Fleming Fjord Formation offers a greater range of stratigraphic and lithologic exposures (representing lacustrine, fluviatile and subaerial environments) than those in which Late Triassic faunas have previously been found. The Fleming Fjord fauna is now known to include a substantial representation of European taxa, including prosauropod (Plateosaurus) and theropod dinosaurs, a turtle (Proganochelys), an aetosaur (Aetosaurus ferratus), a pterosaur (Eudimorphodon), plagiosaurid (Gerrothorax) and capitosauroid (cf. Mastodonsaurus) amphibians, as well as other taxa (a phytosaur, sharks, lungfish, and semionotids). The Fleming Fjord fauna is potentially a key biostratigraphic link between continental sediments of Europe and North America. Evidence of one of the earliest known mammals has been found in the Fleming Fjord Formation. Only the scantiest record of mammalian evolution has been found prior to the Early Jurassic. The cranial and postcranial anatomy of Late Triassic mammals is little understood with the result that current phylogenetic hypotheses suffer from a lack of substantive evidence. At the end of the 1991 season four fossiliferous horizons were discovered in the upper Fleming Fjord Formation; these quarry sites, together with investigation of new, recently identified areas for prospecting, hold great promise for producing additional material of mammals as well as other constituents of this fauna.