November 29, 2013
Fossilized Feces Shows Dino Ancestors Shared Toilets
Brett Smith for redOrbit.com - Your Universe Online
Seeing a pile of feces usually sends people running, but a team of paleontologists has leaped head-long into an ancient collection of poo believed to be about 240 million years old, according to a new study in the journal Scientific Reports.Dubbed the “world’s first public toilet,” the site in Argentina is the earliest known evidence of ancient reptiles sharing a collective dumping ground. Modern animals such as elephants and horses will defecate in a common location to establish territory and decrease the spread of parasites.
"Firstly, it was important to avoid parasites - 'you don't poo where you eat', as the saying goes,” study author Lucas Fiorelli, from the Argentinean research organization Crilar-Conicet, told BBC News. "But it's also a warning to predators. If you leave a huge pile, you are saying: 'Hey! We are a big herd. Watch out!"
At the site, researchers found fossilized feces, known as coprolites, as wide as 15 inches and weighing up to several pounds. While some were tubular, others were more oval-shaped, with colors ranging from a light grey to dark brown-violet, according to the report.
The fossilized feces specimens were found at a density of about 94 poos per square meter and were spread across patches almost 9700 square feet in size. The researchers said the find is rare because feces degrade easily when left out in the open. According to Fiorelli, the tiny time capsules were preserved by a sheet of volcanic ash like the one that famously hit Pompeii.
He noted that evidence at the site pointed to which species may have been responsible for the scatological deposits.
"There is no doubt who the culprit was," Fiorelli said. "Only one species could produce such big lumps - and we found their bones littered everywhere at the site."
The paleontologist said the site was probably used by Dinodontosaurus, an 8-foot-long giant herbivorous reptile that resembled modern rhinos. These large animals were common in the Triassic period, just before the emergence of dinosaurs. The use of a community latrine indicated to the scientists that the reptiles were sociable, herding animals.
"When cracked open they reveal fragments of extinct plants, fungi, and gut parasites," noted study author Martin Hechenleitner, a researches with Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR). "Each poo is a snapshot of an ancient ecosystem - the vegetation and the food chain.”
"This was a crucial time in evolutionary history. The first mammals were there, living alongside the grandfather of dinosaurs,” he added. "Maybe with these fossils we can glimpse into the lost environment which gave rise to the dinosaurs."
"I think the results are interesting. These somewhat bizarre fossils, which may get a few sniggers from people, tell us that distant mammal relatives that lived more than 200 million years ago exhibited some surprisingly mammal-like behaviors," said Brusatte, who was not directly involved in the research. "We didn't know much about the social behaviors, or lack thereof, in Triassic vertebrates. It's very difficult to find unequivocal indicators of social behavior in the fossil record."