Morphological and molecular analyses confirm the presence of the newly described bat species Molossus melini in the Espinal ecoregion from Argentina.

Until now, Molossus melini was known only from its type locality, in the south of Santa Fe province, Argentina. Specimens of this species were collected in 2021 from a roost in a Fraxinus tree of the urban woodland of Paraná city, Entre Ríos province, Argentina. Bat identification was made by comparing external and cranial characters and measurements with those reported in the bibliography and corroborated by a phylogenetic analysis based on the cytochrome b gene. Also, multivariate morphometric analyses showed that cranial measurements, but not external ones, are informative enough to discriminate M. melini from the other Molossus species in Argentina (M. currentium, M. fluminensis, and M. molossus). This new record extends the distribution of M. melini from the south of Santa Fe province by 230 km to the northeast and represents the first record of the species in the Espinal ecoregion.

Supplementary information: The online version contains supplementary material available at 10.1007/s13364-023-00679-1.