New discoveries await diligent paleontologists. For the evidence, look no further than Jakob Vinther, a scientist at the University of Bristol in England, who recently revealed what may be the first example in the field of a non-avian dinosaur flask.
The research, published in the journal Current Biology, offers a look at the back of one psittacosaurus, a dog-sized dinosaur whose fossil remains managed to maintain some semblance of anatomy – enough for Vinther to digitally reconstruct his, uh, butthole.
Investigation of the remains of the Psittacosaurus at the Senckenberg Natural History Museum in Frankfurt, Germany, Vinther realized that he and his colleagues could develop a model for the animal’s cloaca, a multipurpose cavity that facilitates urination, bowel movements and copulation. (Modern birds, crocodiles, and turtles are among those who practice cloacas. The word is Latin for “sewer.”) Vinther collaborated with co-authors such as paleo artists Robert Nicholls and biologist Diane A. Kelly of the University of Massachusetts Amherst on the reconstruction. For reference, Kelly looked at her own collection of animal butts, as well as the active backs of live chickens. After 120 million years, the back of the dinosaur was visible again.
What secrets are there inside? First, the cloaca appears to have a distinct color, which may have attracted potential mates. It also features scent glands, presumably for the same purpose, and a pair of lips around a bean-shaped dorsal lobe, an arrangement that may have resembled a drawn curtain. Of course, Vinther also found a little bit of petrified poop.
Vinther couldn’t say anything else. If this cloaca resembles that of a crocodile, it may have obscured a penis or clitoris, but no trace of genitals was present. Patricia Brennan, an expert on animal genitalia at Mount Holyoke College in Massachusetts, told me The New York Times that it is possible that the lobe simply expelled massive amounts of sperm in a manner similar to some bird species.
A dinosaur penis remains elusive. Only limited conclusions can be drawn from a single sample, but the cloaca is nevertheless another step in understanding the intriguing anatomy of dinosaur buttocks.
[h/t Popular Science]