Protoavis

Protoavis ("first bird") is a problematic Late Triassic (Norian) taxon from the Dockum Group near Post, Texas, originally described by Chatterjee in 1991 as a primitive bird that, if valid, would have pushed avian origins back some 60-75 million years. It is now widely regarded as a nomen dubium. The type material is a jumbled, disarticulated assemblage recovered from a flood-deposited bonebed, and most workers consider it a chimera of more than one animal: its elements have been variously attributed to a non-tetanuran theropod and a ceratosaur, with the skull and neck most likely belonging to a drepanosaurid, so the name cannot be referred to a single organism. Chatterjee has continued to defend the avian interpretation, but it is rejected by nearly all other workers. Its classification among theropods rests on the genuinely dinosaurian elements in the assemblage rather than on the holotype skull.