A 2020 study of SMF R 4970 identified it as an approximately 6–7 year old subadult, and found it preserves the first cloaca known from a non-avalian dinosaur. The positioning of the individual when it died means that both sides of the structure can be seen, although the right side is better preserved. "Psittacosaurus"' cloaca is comparable to those of crocodilians', with a "longitudionally opening vent" and a "rosette pattern of cloacal scales and 129 transverse rows of quadrangular ventral scale", as opposed to the naked area around the cloaca of birds. Like modern crocodilians and birds, dinosaur genetalia were positioned internally. Since SMF R 4970 was not fully sexually mature whe it died, unfortunately the fully matured structure, as well as the sex of the individual and any coacal phallus that may have been present in life, are undetermined.