Extraordinary local diversity of disk-winged bats (Thyropteridae: Thyroptera) in northeastern Peru, with the description of a new species and comments on roosting behavior. American Museum of Natural History 3795

Species of Thyroptera are insectivorous foliage-roosting bats that inhabit lowland moist for-ests (including gallery formations in savanna landscapes) from Mexico to southeastern Brazil. Although four species are currently recognized, only one or two species were previously known to occur at most localities. Recent inventory work in northeastern Peru has documented the local cooccurrence of four species of Thyroptera, one of which is here described as new. The new spe-cies (T. wynneae), which also occurs in Brazil, can easily be recognized by a combination of diagnostic morphological traits. The latter include small size, tricolored ventral pelage, long and woolly hairs between the shoulders, a uropatagium with the proximal half densely covered by long hairs, wing tips sparsely covered by long hairs, a calcar with two lappets and five tiny skin projections between the foot disk and the proximal lappet, a rostrum considerably shorter than the braincase, third lower incisors that are subequal in height to the first and second lower inci-sors, and third lower incisors with two well-developed accessory cusps. We illustrate the crania of all five known species of Thyroptera and provide a key based on craniodental and external characters. Unexpectedly high local diversity of these elusive bats poses a challenge for futur