Protoavis (meaning "first bird") is a problematic taxon known from fragmentary remains from Late Triassic Norian stage deposits near Post, Texas.

Protoavis has been reconstructed as a carnivorous bird that had teeth on the tip of its jaws and eyes located at the front of the skull, suggesting a nocturnal or crepuscular lifestyle.

Many palaeontologists doubt that Protoavis is a bird, or that all remains assigned to it even come from a single species, because of the circumstances of its discovery and unconvincing avian synapomorphies in its fragmentary material.

When they were found at the Tecovas and Bull Canyon Formations in the Texas panhandle in 1973, in a sedimentary strata of a Triassic river delta, the fossils were a jumbled cache of disarticulated bones that may reflect an incident of mass mortality following a flash flood.

The canalicular systems and the cochlear process differ in both taxa, and the vestibular region is relatively small and located in a ventral position to most of the anterior and posterior semicircular canals.

[4] The skull has an extremely narrow parietal with block like dorsal aspect, very broad, T-shaped frontals that form the "lateral wings" that Chatterjee applies to the lack of postorbitals.

[7] There does not appear to be an orbital process present on either bone, and the modifications of the proximal condyle permitting wide range of motion against the squamosal, are not readily apparent.

[3][7][8] These data render the assertion of prokinesis in the skull of Protoavis questionable at best, and it seems most parsimonious to conclude that the specimen displays a conventional opisthostylic quadrate.

Chatterjee omits in his 1987 account of the braincase, the presence of a substantial post-temporal fenestra,[12] which in all Aves (including Archaeopteryx), is reduced or absent altogether,[7][13] and the lack of a pneumatic sinus on the paroccipital.

[13] Furthermore, the braincase possesses multiple characters symplesiomorphic of Coelurosauria, including an expanded cerebellar auricular fossa, and a vagal canal opening into the occiput.

[14] What is preserved of the preorbital skull curiously lacks apomorphic characters to be expected in a specimen, which is allegedly more closely allied to Pygostylia than is Archaeopteryx lithographica.

10.7Ba  Considering the modification of the drepanosaur neck for the purposes of snap-action predation, it becomes more likely that superficial similarities in the cervicals of both taxa are in fact only convergent with Aves.

Chatterjee asserts that the pelvic girdle is apomorphic comparative to archaic birds and displays a retroverted pubis, fusion of the ischium and ilium, an antitrochanter, and the presence of a renal fossa.

The alleged fusion of the ischium and ilium into an ilioischiadic plate is currently not substantiated by the fossils at hand, despite Chatterjee's auspicious illustration to the contrary in The Rise of Birds.

[9][17] The tibia of Protoavis allegedly possesses both a lateral and cranial cnemial crest, though the validity of this claim is subject to question due to the preservation quality of the material.

Curiously, such abbreviation of the ascending process is found in ceratosaurs, and in its general osteology, the Protoavis tarsus and pes, is quite similar to those of non-tetanuran theropods.

Considering how poorly preserved the ulna is, it is entirely premature to make any definitive conclusions as to the presence of quill knobs until such time as more adequate material becomes available.

[14] The taxonomy of Protoavis is controversial, with several palaeornithologists considering it to be an early ancestor of modern birds, while most others in the palaeontological community regard it as a chimaera, a mixture of several specimens.

[4] In the paper, they made a number of corrections involving both Chatterjee's and Currie's own misinterpretations of parts of Troodon cranial anatomy before the particular braincase being described was found.

[11] Protoavis has been reconstructed as a carnivorous bird that had teeth on the tip of its jaws and eyes located at the front of the skull, suggesting a nocturnal or crepuscular lifestyle.

Almost all palaeontologists doubt that Protoavis is a bird, or that all remains assigned to it even come from a single species, because of the circumstances of its discovery and weak avialan synapomorphies in its fragmentary material.

[3][20][21][22] When they were found at a Dockum Group quarry in the Texas panhandle in 1984, in a sedimentary stratum of a Triassic river delta, the fossils were a jumbled cache of disarticulated bones reflecting an incident of mass mortality following a flash flood.

However, only a few parts were found, primarily a skull and some limb bones which moreover do not well agree in their proportions respective to each other, and this has led many to believe that the Protoavis fossil is chimaeric, made up of more than one organism: the pieces of skull appear like those of a coelurosaur, while the femur and ankle bone catalogued under TTU P-9200 and TTU P-9201 respectively suggest affinities to non-tetanuran theropods[23] and at least some vertebrae are most similar to those of Megalancosaurus, a drepanosaurid.

Furthermore, paleobiogeography suggests that true birds did not colonize the Americas until the Cretaceous; the most primitive undisputed bird-like maniraptorans found to date are all Eurasian.

However, coelurosaurs and ceratosaurs are in any case not too distantly related to the ancestors of birds and in some aspects of the skeleton not unlike them, explaining how their fossils could be mistaken as avian.

Smushed and mashed and broken.Archosaur discoveries are comparatively abundant in Texas, and have been recovered in some quantity since E. D. Cope worked the redbeds of the panhandle over a century ago.

The bone bed excavated by Sankar Chatterjee and his students of Texas Tech University, in which Protoavis was discovered, likely reflects an incident of mass mortality following a flash flood.

He interpreted the type specimen to have come from a single animal, specifically a 35 cm tall bird that lived in what is now Texas, USA, between 225 and 210 million years ago.

[9] The botanical evidence indicates that the area was densely forested, and the abundance of both invertebrate and vertebrate material from the site suggests that the locale was in general richly populated by a wide variety of species.

[7] The fossils themselves display significant postmortem damage, and are in some cases so badly crushed and distorted at the hand of geological processes, that accurate interpretation thereof is impossible.