The oldest parasite DNA ever recorded has been discovered in fossilised puma faeces.
A team from CONICET, Argentina’s government research agency, studied a coprolite taken from a rock shelter in the Catamarca Province, northern Argentina.
Radiocarbon dating revealed both the coprolite and the parasitic roundworm eggs preserved inside dated somewhere between 16,500 and 17,000 years ago, near the end of the last Ice Age.
Study leader Dr Romina Petrigh said: “While we have found evidence of parasites in coprolites before, those remains were much more recent, dating back only a few thousand years.
“The latest find shows that these roundworms were infecting the fauna of South America before the arrival of the first humans in the area around 11,000 years ago.”
Ancient mitochondrial DNA analysis confirmed the coprolite came from a Puma concolor and that the eggs belonged to Toxascaris leonine, a species of roundworm still found today in dogs, cats and foxes.
"The large number of eggs of T. leonina and its larva state in the puma coprolite analysed here indicate the high infective capacity of this parasite, involving a high risk for carnivores and for humans,” Dr Petrigh said.
The dry, cold and salty conditions at the site from the onset of the Holocene, our current geological epoch, would have helped reduce the breakdown of the DNA, researchers determined.