First fossil record of Amorphochilus schnablii (Chiroptera: Furipteridae), from the late Quaternary of Peru

A mandible with M(1)-M(3) and associated right and left humeri from a late Quaternary deposit near Palpa in southwestern Peru are identified as remains of the rare bat Amorphochilus schnablii (Chiroptera: Furipteridae), the first fossil record of this species. The combination of characters observed in these fossils can be found only in Amorphochilus, including: very small size, slender mandibular ramus, weak mandibular symphysis, anteriorly rotated ascending ramus, small size of the lower canine, morphology of the lower molars, small rounded humeral head, laterally offset distal articular surface of the humerus, and a prominent distal spinous process on the distal humerus separated from the large medial process by a deep rounded notch. Amorphochilus schnablii currently inhabits the and Pacific coastal region of southern Ecuador, Peru, and northern Chile. This species is one of at least seven bats that are endemic to the Atacama Desert. The endemism among Atacama Desert bats probably reflects their early arrival in the region (perhaps as early as the Miocene), subsequent isolation on the western side of the uplifting Andes, and adaptation to a desert environment.