A Small Pleistocene Mammalian Megafauna from Southern Honduras

Abstract

The final land linkage between the North and South American continents during the Pliocene opened the biogeographic doors for the Great American Biotic Interchange. During this period, reciprocal migrations of dozens of North and South American families of plants, vertebrates, and invertebrates exerted profound influences on previously isolated biotas. Although the exchange has been best documented among mammals, faunas from additional fossil deposits throughout Middle America can help to refine knowledge of the dynamics of the interchange. This paper reports a small Pleistocene mammalian megafauna from a site in southern Honduras near its border with Nicaragua. Four families and genera are represented. Fossils of the glyptodont Glyptotherium floridanum are among the first reported from outside of the United States. Also represented are the giant megatheriid ground sloth Eremotherium laurillardi; the gomphotheriid Cuvieronius tropicus; and a relatively small horse of the genus Equus. Based on these four species, the fauna most likely represents the early Rancholabrean faunal period.