London: Scientists have discovered thousands of fossilised poos left by rhino-like megaherbivores, 240 million years ago in Argentina, suggesting that ancient reptiles gathered together to defecate.
The dung discovered in the "world`s oldest public toilet" was clustered together and provides the first evidence that ancient reptiles shared collective dumping grounds, researchers said.
Elephants, antelopes and horses are among modern animals who defecate in socially agreed hotspots - to mark territory and reduce the spread of parasites.
Researchers found fossilised feces as wide as 40cm and weighing several kilogrammes in seven massive patches across the Chanares Formation in La Rioja province.
Some were sausage-like, others pristine ovals, in colours ranging from whitish grey to dark brown-violet, the BBC News reported.
"There is no doubt who the culprit was," said Dr Lucas Fiorelli, of Crilar-Conicet, who discovered the dung heaps.
The perpetrator was Dinodontosaurus, an eight-foot-long megaherbivore similar to modern rhinos.
These animals were dicynodonts - large, mammal-like reptiles common in the Triassic period when the first dinosaurs began to emerge.
The fact they shared latrines suggests they were gregarious, herd animals, who had good reasons to poo strategically, said Fiorelli.
The animals defecated together to avoid parasites and leaving a huge pile intimidated predators into thinking they were up against a big herd.
The predator in this case was the formidable Luperosuchus, a crocodile-like carnivore up to 8m in length.