First fossil record of a bat (Chiroptera, Phyllostomidae) from Uruguay (Plio-Pleistocene, South America): a giant desmodontine

The family Phyllostomidae is a monophyletic clade of Neotropical bats with diverse feeding strategies including sanguivory (subfamily Desmodontinae). The fossil record in open sites of South America (SA) is scarce and patchy. Molecular estimations suggest origination of vampire desmodontines in late Paleogene of SA, but are only recorded in the latest Pleistocene and Holocene. Here we describe the first fossil record of bats for Uruguay from an open site (Raigon Formation, Plio/Pleistocene) based on a complete humerus, accompanied by a comparative analysis, and paleoclimate and paleobiogeographic considerations. Quantitative comparisons show that it belongs to a population of large bats similar to the extinct giant Desmodus draculae. It is not younger than middle Pleistocene suggesting the absence of this clade in the Tertiary of SA is a taphonomic bias. It is the oldest record of a vampire desmodontine (Desmodus) from SA, suggesting a previous history and provides empirical evidence of migration from SA to NA of Neotropical vampires linked to the Great American Biotic Interchange. Tropical to subtropical climates are suggested at these latitudes of SA during the deposition of the bearing beds. Potential prey are medium-large mammals (ground-sloths, notoungulates, litopterns, and large rodents, among others) and large terrestrial birds (terror-birds).