Feathers, Tianyulong? Really?

tianyulong-bristly-dinosaur

So the recent discovery published in Nature last week by researchers from the Institute of Geology in Beijing of an apparently bristly 130 million-year-old ornithischian fossil has had quite the rapturous reception by the international media. The palaeontologists, however, prefer to keep their excitement cautious, quietly asserting, “Whatever, man, I already knew about this like twelve months ago,” and “Haven’t we already done all this like seven years ago? LOL.” Paraphrasing with nonexistent LOLs as I might be (because I dream of scientists who say LOL), the point is that according to the experts, there is far more to this story than just, “Holy shit, this particular bitch is not supposed to have feathery bits, is it? So all early dinosaurs were covered in feathers now?”

tianyulong-specimen-480

But before we get to the cautionary part, a bit of background information first. The features of the fossilized specimen in question, dubbed Tianyulong confuciusi, that have everyone talking are the three distinct patches of long, hollow filaments at the base of the tail, suggesting the presence of a kind of “dinofuzz” coating. Of course feathered dinosaurs and dinofuzz are nothing new, one of the more famous examples of this being the plumaged Velociraptor, but what is remarkable about this new fossil is that the cat-sized Tianyulonh was an ornithischian and that is something.

The significance of this discovery lies in a fundamental separation in dinosaur types, having split at the base of the Dinosaurian family tree into two groups, the saurischias, which include the carnivorous bipedal theropods such as the Tyrannosaurs and Laelaps etc, and the lovely sauropods, and the ornithischians, which were quadrupedal herbivores such as the various horned, armoured, and duckbilled dinosaur varieties. Within the saurischias group is the coelurosauria clade containing theropods such as Raptors and the Archaeopteryx etc who, with their upright stance, birdlike hand postures and feathery coats, have long been considered the ancient ancestors of today’s birds. But for the distinctly unbird-like ornithischians (not to mention a basal species like the Tianyulong) to be found with dinofuzz when they were assumed to have been strictly scaly, and therein lies the peculiarity of this discovery.

But as exciting as this Tianyulong fossil is, it’s certainly not as ground-breakingly unique as the accompanying hype would have you believe, a controversial precedent having been discovered some seven years earlier. The first ornithischian fossil to show signs of filamentous integumentary structures was discovered in 2002, a Psittacosaurus, displaying sparsely distributed examples at the base of its tail. Rife with controversy due to the questionable legality of its export and the possibility that the bristles were in fact well-positioned leaves, it has been relatively left alone by palaeontologists. Until now, of course.

But this is the only example amongst a number of fleshy and skeletal Psittacosaurus fossils to show signs of dinofuzz, and together with the Tianyulong it raises the question: have we not seen more fuzzy ornithischian fossils because soft tissue rarely survives in the fossil record? Or did the ornithischians outgrow their fuzz, like a kind of “reverse kitten,” thereby effectively reducing their potential fuzzy fossil representatives to merely those in the short-lived juvenile state? Alternatively, was their fuzz selectively distributed, ie in crest or ridge-form, and therefore managed to avoid appearing in the fossils uncovered so far? Perhaps, but only more fossilised fuzzy ornithischian specimens will tell.

Visit Dave Hone’s Archosaur Musings and SV-POW! for much better explanations of all this, and thanks, Not Exactly Rocket Science.

– bec

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2 Comments

Filed under Archosaurs, Fossils, Museum Stuff, New Species!

2 responses to “Feathers, Tianyulong? Really?

  1. *raises hand*

    Sauropod are, of course, saurischians. :-)

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