A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs.

A Middle Jurassic abelisaurid from Patagonia and the early 6 diversification of

An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina

BACKGROUND Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodonto...

A New Basal Sauropod Dinosaur from the Middle Jurassic of Niger and the Early Evolution of Sauropoda

BACKGROUND The early evolution of sauropod dinosaurs is poorly understood because of a highly incomplete fossil record. New discoveries of Early and Middle Jurassic sauropods have a great potential to lead to a better understanding of early sauropod evolution and to reevaluate the patterns of sauropod diversification. PRINCIPAL FINDINGS A new sauropod from the Middle Jurassic of Niger, Spinop...

Type Material of the Type Species of the Classic Theropod Footprint Genera Eubrontes, Anchisauripus, and Graliator (early Jurassic, Hartford and Deerfield Basins, Connecticut and Massachusetis, U.s.a.)

The classic Early Jurassic age theropod footprints Eubrontes giganteus. Anchisauripus sillil1Ulni. and Grallator parallelus were established by Edward Hitchcock in 1836-1847 and are the type ichnospecies of their respective ichnogenera. We identify, describe, and figure the type specimens in detail for the first time since they were named. We also figure and describe the other elements of the t...

A late-surviving basal theropod dinosaur from the latest Triassic of North America.

The oldest theropod dinosaurs are known from the Carnian of Argentina and Brazil. However, the evolutionary diversification of this group after its initial radiation but prior to the Triassic-Jurassic boundary is still poorly understood because of a sparse fossil record near that boundary. Here, we report on a new basal theropod, Daemonosaurus chauliodus gen. et sp. nov., from the latest Triass...