Despite the opening scene in the movie Jurassic Park where a team of paleontologists and their field hands sweep dirt (which looked like kitty litter) off a completely articulated “Velociraptor,” it is actually quite rare to get anything even remotely complete and articulated from the fossil record. We paleontologists are often ecstatic if we get over 50% of a skeleton, and the higher that number creeps, the bigger our grins get. As someone who has had the good fortune to find and name two dinosaurs, believe me — even a 40% complete skeleton is enough to throw a party about. And that’s just if the skeleton is in pieces, let alone articulated in any semblance.
Hence the eternal question, “how do you really know what you have? Aren’t you just speculating?” The answer to that question involves cars and trip to the junkyard. If you were an expert on automobiles, and you went to a junkyard and found bits and pieces of cars, you could still have some very good approximations of what was in the scrap heap. You might, from pieces of engine block and chassis undergirding, be able to get down to the make or model, and even have a fair idea of how large the car was. So it is with dinosaur skeletons. Many of us know our anatomy well, and so even if the whole animal isn’t there, we can often say a lot, factually, about what was probably or almost certainly there.
Therefore, when we do find a complete or nearly complete dinosaur, it is truly rare and mind-blowing. Such is the case with the newly discovered predatory dinosaur, Sciurumimus albersdoerferi, reported in the journal PNAS by Oliver Rauhut and colleagues. The genus name, by the way, essentially translates to “squirrel mimic.” This little, post-hatchling dinosaur was discovered in the same Late Jurassic sediments from Germany as its more famous feathered relative, Archaeopteryx. This animal is complete, and I do mean complete. To put this in the proper perspective, bear in mind that the delicate bones of the hands and feet and nearly every single tail (caudal) vertebra, elements that are normally lost to time, are preserved. In fact, even the hyoid bone, the splint-like tongue-anchoring bone in all jawed vertebrates, is present, tucked just behind and beneath the chin.
This little predator is not on the line of dinosaurs that led to the birds (birds are dinosaurs?). Instead it belongs to a family of predatory dinosaurs called megalosauroids that share more deeper, distant common ancestors with the coelurosaur line that led to birds. And here’s where things get truly weird: this little predator had filamentous proto-feathers preserved at the base of its tail and along parts of its body. Given the position of this predatory dinosaur in the family tree, it strongly suggests that all or nearly all predatory dinosaurs had some kind of feathers, proto-feathers, or filamentous structures adorning their bodies. And here again, we have an animal with no hope of flying (the arms are much too small to have been effective wings) still sporting plumage or its equivalent.
With hindsight, we might now say that not only was Jurassic Park a bit off the mark with how it portrayed dinosaur discoveries, but it was also, perhaps, too conservative with its predatory dinosaurs, who might have sported filaments and feathers. Perhaps this is something Steven Spielberg and friends could fix with the magic of CG when Jurassic Park is re-released on some future date in ultra hi-def surround holographic discs that do not yet exist. Until then, you could always watch the parts with Velociraptor through a feather duster.