Paleoparasitological analysis of rodent coprolites in holocenic samples from Patagonia, Argentina.

The aim of the present study was to examine the parasite fauna present in rodent coprolites collected from Cerro Casa de Piedra (CCP7), located in Perito Moreno National Park (P.N.PM., 47 degrees 57'S and 72 degrees 05'W), Santa Cruz Province, Argentina. Eight coprolites obtained from the layer XIII of CCP7, with an antiquity considered as 7,920 +/- 130 yr B.P, were examined for parasites. Each coprolite was whole processed, rehydrated, homogenized, spontaneously sedimented, and examined using light microscopy. Eggs of parasites were measured and photographed. All the samples were parasitized by nematodes, with 267 eggs of Trichuris sp., 24 eggs of an aspidoderid, and 3 capillariid eggs. The rodent host was tentatively identified as a species of Ctenomys, the hypogeic rodents endemic to South America. The finding of Paraspidodera in Patagonian samples represents new evidence that strengthens the co-phylogenies between nematodes of this genus and Ctenomys and reinforces the value of parasites as tags in paleoparasitology.