Experts have pieced together the fossilized remains of a giant sloth discovered in 2010 in a cenote, or sinkhole, in Quintana Roo and describe it as a new species.
The bones of the animal, estimated to have roamed the region more than 10,000 years ago, were not removed from the cenote until 2014. National Institute of Anthropology and History (INAH) underwater archaeologist Carmen Rojas Sandoval led a team that extracted the animal’s skull, its jawbone, nine vertebrae, three long bones, three ribs and seven claws.
Experts had to wait two years before the fossilized samples could be properly examined. During that time they had to transition from their freshwater cenote environment to one of distilled water. After that, a gradual dehydration process started in April 2015.
Specialists at the Mass Spectrometry Lab (Lema) at the National Autonomous University of Mexico (UNAM) were then able to carbon-date the sloth’s remains, concluding that it had lived between 10,647 and 10,305 years ago.
Direct observations made in the cenote at a depth of between 50 and 55 meters under water have concluded that the animal’s skeleton is mostly complete. This has led to the theory that the sloth fell into the cenote when it was dry, or mostly so.
The deepest recesses of the cenote started to fill up with water 10,000 years ago when Caribbean Sea levels started rising, a process that would completely submerge the network of caves in the Yucatán peninsula.
That same process allowed the “extraordinary conservation” of the sloth’s remains, as well as those of countless other mammals and humans that lived at the time in that part of the country. The sloth, nicknamed Pote for the cenote called Zapote in which it was found, is just one of 14 fossilized sloth remains found in 11 submerged caves so far.
A second expedition is scheduled for next year when INAH expects to retrieve the rest of Pote’s skeleton. The first expedition was funded by the institute, along with the Desert Museum of Coahuila, Heidelberg University in Germany and the Quintana Roo-based American Prehistory Institute.
The new species, Xibalbaonyx oviceps, has been named after the place it was found and its physical characteristics. Xibalba is the Maya term for the underworld, the interpretation given by that culture to the network of underwater caves that crisscrosses the Yucatán peninsula. Onyx is claw in Greek, while ovum describes the ovoid shape of the skull.
Mexico News Daily