Triassic Toilet

Coprolites (fossilised faeces) are trace fossils that give an insight into the diet and digestive processes of long-extinct animals that we cannot get from their body fossils as the soft parts of an animal generally aren't preserved as fossils.

Palaeontologists working in Argentina have found a communal toilet area used by Dinodontosaurus with a remarkable density of 94pm^-2 (poos per square metre!).  The geological implications of this are fascinating in terms of what it can tell us about the behaviour of an early predecessor of the dinosaurs.  The benefits of having a defined place for a toilet are obvious as parasites may be less of a problem and food and faeces aren't mixed. It could also have been a way for the Dinodontosaurus to ward off the crocodile-like predator Luperosuchus.

What I find interesting about this is that it implies some type of social organisation for these animals, something we don't see in modern cold-blooded animals.  What do you think caused these animals to behave in this way?