New remains of Megatherioidea (Mammalia, Xenarthra) from the tropical Middle Miocene La Venta site in Colombia

Abstract

Sloths (Mammalia, Xenarthra, Folivora) are one of the most diverse clades of mammals that can be found in the Middle Miocene assemblage of La Venta site (Laventan South American Land Mammal Age, SALMA; ca.13.5–11.8 Ma), in central Colombia. Here, we provide a description of a new a ground sloth, Megatherioidea gen. et sp. indet. from La Venta site, represented by a partial maxilla with teeth that exhibit shared characteristics with other sloths found in the Early Miocene (Santacrucian SALMA; ca. 18–16 Ma) from Argentina: Schismotherium, Pelecyodon, Hyperleptus, Hapalops, and Analcimorphus. The new specimen likely represents a new taxon, however additional and more complete material is necessary to properly evaluate this taxonomic hypothesis. We consider the specimen to be important due to its possible links with other sloth lineages from southern South America. The new specimen increases the taxonomic diversity of folivores from the Middle Miocene of the La Venta site, Colombia and provides further evidence that Megatherioidea were widely distributed throughout South America since the Middle Miocene.