CENOTES, CAVES, AND SLOTHS: PLEISTOCENE SLOTH DIVERSITY ON THE YUCATAN PENINSULA, MEXICO AND BELIZE

ABSTRACT:

Exploration of both dry and submerged caves in the Yucatan Peninsula by cave divers has revealed a high diversity of Pleistocene giant ground sloths, representing all four families. Researchers working in the caves of Quintana Roo, Mexico, have identified up to five genera of sloths; a sixth genus is known from Belize. Three of the sloths, Nohochichak xibalbahka, Xibalbaonyx oviceps, and X. exenferis (if valid) are endemic to the peninsula. Preliminary dating indicates the genera were not all sympatric, with Nothrotheriops and a mylodontid occurring in the north during the last glacial maximum in what was likely an arid habitat, and with Eremotherium in forested central Belize. The northern part of the peninsula supported at least two megalonychids in earlier millennia in what was likely a more forested habitat. Better dating of known specimens is needed, along with stable isotope analyses, to clarify the history and ecology of sloths in the Yucatan.