Thyropteridae Miller, 1907

Velazco, Paúl M. & Patterson, Bruce D., 2019, Small Mammals Of The Mayo River Basin In Northern Peru, With The Description Of A New Species Of Sturnira (Chiroptera: Phyllostomidae), Bulletin of the American Museum of Natural History 2019 (429), pp. 1-69 : 43

Family Thyropteridae Miller, 1907

The Neotropical family Thyropteridae includes five species characterized by small size, the presence of a circular disk on the sole of each foot, and an oval or circular disk attached by a short pedicle to the base of each thumb (Velazco et al., 2014). One species was recorded at one locality.

Thyroptera tricolor Spix, 1823

VOUCHER MATERIAL: Tingana: 1 adult female ( FMNH 203644 ) ; see table 18 for measurements.

IDENTIFICATION: We consulted descriptions and measurements of Thyroptera tricolor provided by Wilson and Findley (1977), Pine (1993), Solari et al. (2004), Bezerra et al. (2005), Lim et al. (2005), Gregorin et al. (2006), and Velazco et al. (2014). Three subspecies are currently recognized in T. tricolor : T. t. albiventer (southern Mexico southward to lowland Colombia and Ecuador), T. t. juquiaensis (known only from the type locality in the state of São Paulo, Brazil), and T. t. tricolor (Amazon basin of Brazil and Peru, and the Guianan Shield of Guyana, French Guiana, Surinam, and Venezuela) ( Wilson and Findley, 1977; Wilson, 2008a). Velazco et al. (2014) identified our Mayo River basin specimen as T. tricolor . This specimen exhibits most of the diagnostic characteristics of the species: unicolored whitish ventral pelage; proximal portion of the fore- arm sparsely haired; circular adhesive disk on the thumb; calcar with two lappets that project posterolaterally from the shaft of the calcar; I2 mesial cusp larger than the distal cusp; both cusps on I2 obliquely arranged relative to the long axis of the toothrow; P1 circular in occlusal view; i3 with two faintly developed accessory cusps on each side (Velazco et al., 2014). One of the diagnostic characteristics of the family Thyropteridae is the lack of postorbital processes, which is seen in all known species ( Wilson, 2008a). However our specimen possesses wellmarked postorbital processes on both sides of the skull. The presence of postorbital processes in our specimen could be the result of individual variation or might be indicative of a new species, but without a more comprehensive study that includes molecular data, we continue to identify this individual as a member of the nominate subspecies. With the exception of its postorbital processes, our specimen conforms to previous descriptions of the nominate subspecies and its measurements fall within the range of size variation previously documented.