It is the smallest member of its genus. The holotype weighed. The length of its head and body together is. Its forearm is long. Its ears are short and narrow, at long. Like other monkey-faced bats, it wings attach to the body near the spine rather than at the sides of its body, it has a defined sagittal crest, and it has massive canine teeth. It has "striking" red eyes. Its flight membranes are black and white. Its head, face, and back is blackish in color. The fur on its ventral side is yellowish. The ears are black, while the fur at the base of each ear is white. Like other members of its genus, its dental formula is. Flannery called it the "most attractive" member of its genus due to its striking coloration.
Biology
As only one individual has been encountered, little is known about its biology. The holotype was a lactating female encountered in May. Pteralopex is a very old genus of bats, and the monkey-faced bats evolved in relative isolation to fill ecological niches occupied by large mammals in continental ecosystems.
It is assessed as critically endangered by the IUCN. If it is not extinct, the IUCN estimates that its population contains no more than 50 adults in a single population. Extensive surveys in 2015 failed to locate additional individuals, making the holotype collected in 1990 the only documented individual. In 2010, the United States Federal Government received a petition from WildEarth Guardians to list the montane monkey-faced bat, as well as 14 other species of bat, under the Endangered Species Act. It is still under review for consideration under the Endangered Species Act. Scientist Diana Fisher coauthored a paper on the probability of rediscovering mammal species that have not been documented in several years, including the montane monkey-faced bat. Later, in an interview, she noted that several species of mammal feared extinct had a decent chance of rediscovery, specifically mentioning the montane-monkey faced bat and Alcorn's pocket gopher. In particular, Fisher and coauthor Blomberg found that time missing was an important factor in mammal rediscovery, with species that haven't been missing as long more likely to be rediscovered. Mammals with larger ranges are also more likely to be rediscovered after "extinction," as well as mammals thought to have gone extinct due to habitat loss as opposed to overhunting. In 2015, the nonprofit organization Bat Conservation International awarded a Grassroots Grant to Australian researchers to confirm where surviving populations exist. However, the holotype is still the only known example of this species.
