Protoavis

Type Species: Protoavis texensis

Classification: Dinosauria - Saurischia - Theropoda

Time Period: Late Triassic

Location: Texas

Diet: Carnivore

Protoavis’ name means ‘first bird,’ and it hails from the Norian stage of Late Triassic Texas. This dinosaur (or dinosaur-like creature, depending on who you talk to) continues to be the topic of many collegiate barroom debates. If Protoavis is a bird, as its discoverer Sankar Chatterjee insists, then it pushes bird evolution back 75 million years from the Jurassic Period. Archaeopteryx of the Jurassic Period has been traditionally viewed as the first known bird, sprouting from theropod dinosaurs, but if Protoavis precedes it, then bird origins are pushed back to the Late Triassic. 

We don’t know much about Protoavis, because its remains are sketchy and smashed. Reconstructions picture it as a 35-centimeter tall bird that lived in modern-day Texas some 210 million years ago. It had teeth on the tip of its jaws and eyes located at the front of the skull, which suggests a nocturnal or crepuscular (‘twilight’) lifestyle. The presence of feathers is suggested, but not confirmed, by what appear to be ‘quill knobs.’ Quill knobs are the attachment points for flight feathers found in some modern birds and non-avian dinosaurs. It had a braincase similar to the later theropod dinosaur Troodon – hailed as one of the smartest of all dinosaurs – and its otic capsule may be arranged in bird-like fashion with three distinctly-arranged foramina. However, the presence of a post-temporal fenestra in the braincase is either foreign or reduced in all birds, including Archaeopteryx. The braincase has a lot of similarities to those of the coelurosaurian dinosaurs, and its hand-bones are decidedly non-avian. Despite these differences, Chatterjee and other paleontologists – though a minority – insist that Protoavis really is the first known bird. As Chatterjee writes, “The most remarkable thing about Protoavis is that, although it predates Archaeopteryx by 75 million years, it is considerably more advanced than Archaeopteryx… Protoavis is more closely related to modern birds than is Archaeopteryx.” That’s quite the statement, and it’s no surprise that the majority of paleontologists cry anathema.

Chatterjee’s detractors deny that Protoavis is a bird; they’ll argue that it’s just a weird type of archosaur, or even a ‘chimera,’ a combination of different creatures into a whole that had no basis in reality. As one paleontologist quipped, “The most parsimonious conclusion to be inferred from [the] data is that Chatterjee’s contentious find is nothing more than a chimera, a morass of long-dead archosaurs.” If he’s right, then Chatterjee’s specimen is comprised of bits and pieces of different organisms built together into a Late Triassic Frankenstein. Not all detractors believe it’s a chimera, however; many believe that Protoavis truly is a real animal from the Triassic, but they question the identification of quill knobs. Perhaps the quill knobs were actually something else! In other cases, however, those same paleontologists who decry the quill knobs on Protoavis will praise the very same thing on other creatures! Take, for example, Concavenator, which lived 130 mya and predated Archaeopteryx by about twenty million years. It, too, had ‘quill knobs’ like Protoavis, and paleontologists were more than happy to identify them as feather attachments. The magazine Nature reports, “[It] is the bumps on the dinosaur’s arms that have caused a stir: the researchers think that they may have been part of structures that anchored quills to the creature’s bones.” According to the standards applied to Concavenator, there’s no reason to question the quill knobs of Protoavis. It becomes apparent that the criticism directed towards Chatterjee has less to do with scientific reasons and more to do with philosophical ones. As Michael Benton explains, acknowledging Chatterjee’s interpretation of Protoavis’ quill knobs would wreak havoc on standard evolutionary theory: “[If] Protoavis is a bird, then the point of origin of the group [of birds] moves back to the late Triassic, and that would distort many parts of the phylogeny, not only of birds, but also of Dinosauria in general.” We can delight in the discovery of Concavenator, because it’s enlightening and invigorating; but we must resist the same rules applied to Protoavis, because doing so would put the whole ‘birds evolved from dinosaurs’ paradigm on uncertain footing. 

Of course, birds could still be evolved from dinosaurs, just far earlier than expected and from more primitive theropod stock; but it would also open the possibility that birds are ‘common ancestors’ of dinosaurs just as chimpanzees are ‘common ancestors’ of humans: we’re cousins, but not descended from one another. Many ornithologists, who don’t like the idea of birds descending from dinosaurs, trumpet Protoavis as a banner, insisting that birds found their origins with archosaurian relatives of the first dinosaurs. Thus we can see why Protoavis has become such a hot topic. Despite its detractors, however, some paleontologists do agree with Chatterjee and argue that birds still evolved from dinosaurs – but they did so in the Late Triassic around the same time that theropods were in their genesis.