Analyzing a coprolite, or a piece of fossilized dung, of a puma in the mountainous areas of the province of Catamarca, South America, a team of scientists from the National Council of Scientific and Technical Research (CONICET) has identified what can be considered the oldest find of traces of a molecular parasite and encoded the oldest DNA sequence of a gastrointestinal nematode parasite of wild mammals.
Researchers have in fact used radiocarbon dating to discover the age of nematode eggs placed within the coprolite reaching the conclusion that they date back to a period between 16,570 and 17,000 years ago. The same analysis of mitochondrial DNA revealed that it was feces expelled from a Puma concolor.
The analyzes also revealed that the eggs belonged to a species of nematode called Toxascaris leonina. This nematode is still present today in the digestive systems of dogs, cats and foxes.
DNA analysis was possible thanks to the conservation conditions of the coprolite that has spent all these years in an extremely dry, cold and salty environment at the Peñas de las Trampas site in the Andean region of the Puna, an environment that was once very much more humid.
Romina Petrigh, the researcher who led the study together with Martín Fugassa, underlines the importance of the research: “While we have previously found evidence of parasites in coprolites, these remains were much more recent, dating back to a few thousand years. This latest finding shows that these nematodes were already infecting South American fauna before the first humans arrived in the area about 11,000 years ago.”