Common Name: Thumbless or Smoky Bats
Taxonomy: Infraorder Yangochiroptera, Superfamily Vespertilionoidea, 2 genera 2 species
Distribution: from southern Central America south to southern Brazil, Northern Chile, and Trinidad
Fossil Record:
Size Range: Small, head - body length 33 - 58 mm, forearm 30 - 40 mm, tail 24 - 36 mm
Characteristics:
Called Smoky Bats because of their grey pelage. Coarse fur.
Large funnel-shaped ears. Base of the ears cover the eyes. Small tragus has a broad base is somewhat triangular.
Slender build and long wings
The thumb is greatly reduced and functionless (hence the common name Thumbless Bats), it is entirely enclosed in the membrane in front of the forearm.
long legs, short feet
snout is truncated and the end forms a disk or pad
no nose-leaf, nostrils are close together, oval or triangular, and open down
Premaxillaries are partially cartilaginous and canines are reduced
Dental formula is i2/3, c1/1, pm 2/3, m 3/3 = 36
Insectivorous
Have been found in caves and buildings
Most of range is tropical but have been found in arid sections of north-western South America
(from the books "Bats - A Natural History" and from "Walker's Bats of the World")