ADDITIONAL BATS FROM THE MIDDLE MIOCENE LA VENTA FAUNA OF COLOMBIA

Abstract

By screenwashing sedimentary rocks from the middle Miocene Villavieja Formation in the Río Magdalena valley, Huila Department, Colombia, yielded diverse bat fossils that contribute to the understanding of the approximately 12-13 million-year-old La Venta fauna. These newly collected specimens encompass an emballonurid, a noctilionid, three phyllostomids, a thyropterid, three molossids, and a probable vespertilionid. They originate from a stratigraphic level known as the Monkey Beds, dated between 12.5 million and 12.2 million years. Noteworthy findings include upper molars of Notonycteris magdalenensis, affirming its close relation to Vampyrum and Chrotopterus, and a novel species of Notonycteris, characterized by smaller size than N. magdalenensis based on two lower molars. Two upper molars from a primitive nectar-feeding bat introduce a new taxon of Phyllostomidae (Glossophaginae), representing a new genus and species and marking the only Tertiary record for this group. Another molossid, as yet unidentified, expands the bat diversity, and an unidentified probable vespertilionid constitutes the first family record in the La Venta fauna. In total, the La Venta fauna now encompasses 14 bat species, including some that remain indeterminate.