New discoveries await diligent paleontologists. For evidence, look no further than Jakob Vinther, a scientist at the University of Bristol in England who recently revealed what could be the first example of a non-avian dinosaur field.
The research, which was published in the journal Current biology, offers a look at the back of a psittacosaurus, a dino the size of a dog whose fossilized remains managed to retain an appearance of anatomy – enough for Vinther to reconstruct digitally, uh, butthole.
Examining the remains Psittacosaurus at the Senckenberg Museum of Natural History in Frankfurt, Germany, Vinther realized that he and colleagues could develop a model for the animal’s cloaca, a multifunctional cavity that facilitates urination, bowel movements, and copulation. (Modern birds, crocodiles, and turtles are among those that carry the sewer. The word is Latin for “sewer.”) Vinther worked with co-authors as a paleoartist. Robert Nicholls and University of Massachusetts Amherst biologist Diane A. Kelly on reconstruction. For reference, Kelly looked at her own collection of animal buttocks, as well as the active back of live chickens. After 120 million years, the back of the dinosaur was visible again.
What secrets are hidden inside? First of all, the cloaca seems to have a distinct color, which could have attracted potential colleagues. It also contains scented glands, probably for the same purpose, and a pair of lips that surround a bean-shaped dorsal lobe, an arrangement that could have looked like a drawn curtain. Of course, Vinther also found some fossilized poop.
Beyond that, Vinther couldn’t tell. If this cloaca is like a crocodile, it may have hidden a penis or clitoris, but there were no traces of genitals. Said Patricia Brennan, an expert in genitals at Mount Holyoke College in Massachusetts New York Times that the lobe may have simply removed massive amounts of semen in a similar way to some bird species.
A dinosaur penis remains elusive. Only limited conclusions can be drawn from a single sample, but the sewer is still another step in understanding the intriguing anatomy of dinosaur buttocks.
[h/t Popular Science]