They reported that arrows penetrated the creature's skin only with difficulty. Ameghino posited the creature might be a surviving ground sloth. Preserved skin samples from prehistoric ground sloths showed hard dermal ossicles that would have protected against prehistoric predators and, possibly, arrows and bullets as well. Ameghino named the purported modern ground sloth Meomylodon listai in Lista's honor. In the early 1970s Ralph M. Wetzel and co-workers from the University of Connecticut discovered living specimens of the Chacoan Peccary, which he named Catagonus wagneri .
Peccaries are close relatives of pigs and boars.
Prior to Wetzel's find this type of peccary was known only from fossils and had been thought to have died out ten thousand years ago. Wetzel found the living specimens in Patagonia after hearing native stories. The natives called it the tagua . The Chacoan Peccary is the largest of the three known living species of peccary. There are significant differences in the chromosome numbers of the Chacoan peccary and the other two species, indicating they are not closely related.