Fossilised reptile poo incorporates 200-million-year-old parasites

Fossilised faeces of a crocodile-like predator dwelling 200 million years in the past reveal the animal was contaminated with a number of parasite species. Proof of historic parasites is notoriously laborious to seek out within the fossil file, so this discovery may also help give us an image of how they unfold from species to species.

Parasites infect animals’ comfortable tissues, which not often protect properly over time. So Thanit Nonsrirach at Mahasarakham College in Thailand and his colleagues analysed a pattern of fossilised dung, additionally referred to as a coprolite, that was first unearthed in 2010 from the Huai Hin Lat Formation in north-eastern Thailand.

“I wished to know what’s contained in the coprolite, so I made a decision to chop it open and look at its inside construction,” says Nonsrirach.

The form and contents of the faeces helped the researchers slim down which creature it got here from. They first photographed and measured the coprolite earlier than hardening it with an epoxy resin. They then lower the log – 7 centimetres lengthy and a pair of centimetres thick – into skinny, salami-like slices.

When the group examined the slides underneath the microscope, they discovered parasite eggs in a variety of dimensions and shapes trapped within the droppings. The eggs had been largely spherical and oval, and across the thickness of a human hair. The group suspects as many as six parasite species – together with intestinal worms referred to as nematodes from the order Ascaridida – are represented within the historic faeces.

The researchers concluded that the excrement was most likely left by an armoured, semi-aquatic reptile that seemed like and lived equally to a contemporary crocodile. “Contemplating that crocodiles appeared round 100 million years in the past through the Late Cretaceous, it’s doubtless that the coprolite got here from a crocodile-like animal or one which co-evolved with crocodiles, equivalent to phytosaurs,” says Nonsrirach.

Primarily based on the stays of historic vegetation and animals additionally discovered within the space, the researchers estimate the specimen is from the early Late Triassic Epoch, round 237 million to 208 million years in the past. “This discovery is essential for understanding the number of parasites and the way they interacted in historic ecosystems,” says Nonsrirach. He suspects the animal ingested the parasites by feeding on contaminated fishes, amphibians or different reptiles.