image: Alberto Nava at 145-ft depth in Hoyo Negro, inspecting a forelimb of an extinct Shasta ground sloth, one of two sloth species found in the cave. The Shasta ground sloth has not previously been found so far south in the Americas. This image relates to a paper that appeared in the May 16, 2014, issue of Science, published by AAAS. The paper, by James C. Chatters at Applied Paleoscience and DirectAMS in Bothell, Wash., and colleagues was titled, "Late Pleistocene Human Skeleton and mtDNA Link Paleoamericans and Modern Native-Americans." view more
Credit: [Photo by Roberto Chavez Arce]