The discovery of the first preserved dinosaur anus in China in October 2020 has conveyed new information to paleontologists worldwide. According to new research, this part of the body, was used for multiple functions, earning the name, “cloacal ventilation”.
Accordingly, the rear part of dinosaurs was used for the excretion of feces and urine, but also for mating and laying eggs. The remains found were so well preserved, that scientists believe they found two lumps, which possibly housed odorous glands used to attract mates.
Although the rear of the dinosaurs, is very similar to some of the animals living today, – as is the case with some crocodiles – scientists guarantee that the discovery is totally “unique” and “special”. In an interview with Live Science, University of Bristol paleontologist Jakob Vinther stated that the anatomy of the dinosaur’s anus is something never seen before.
In Vinther’s view, the prehistoric cloaca discovered last year is nothing like the rear opening of the birds, which would be the closest living relatives of the dinosaurs, and also has some differences compared to the rear of other reptiles.
The anus discovered belongs to Psittacosaurus, a species of bristly tail, the size of a Labrador and a close relative of the Triceratopes. According to historians’ data, this species would have inhabited Earth during the Cretaceous period, which occurred between 145 million and 65 million years ago.
Jakob related, that the surprisingly preserved cloaca was discovered while he and his research partner Robert Nicholls were trying to find out what color the Psittacosaurs’ skin was. Interestingly enough, no soft tissue of the reproductive system could be identified, which made it impossible to determine the sex of the animal.
Even so, Vinther believes that this species of dinosaur was more likely to copulate, unlike some birds that just bump their buttocks in a “cloacal kiss” to reproduce.
According to the researchers, there is evidence that the orifice was covered in dark hues of melanin, which would provide antimicrobial protection for this region of the body and prevent dinosaurs from developing infections in the cloaca.
