By Bret Weinstein and Phil Myers
This family is composed of a single genus containing 12 species. Their distribution includes both tropical forests and arid tropical regions in Africa and Southeast Asia.
Nycterids are small to medium in size. All have a peculiar deep longitudinal slit running along the top of the rostrum posterior to the nose. Its borders are fleshy and complex and partially conceal the opening. The function of this pouch is not known, but it has been suggested that it might somehow be involved in echolocation (like the noseleaf of phyllostomids, a structure that is absent in nycterids). Most slit-faced bats are orange, brown, or gray. They have large, oval ears with a small but well-developed tragus.
The skulls are distinctive due to a 
deep depression between the orbits, which probably contains the pouch described above. Postorbital processes are present but hard to distinguish because of the unusually broad supraorbital ridges extending over the orbits. The premaxillae are made up of palatal branches only. These are well developed and completely fill the space between the maxillae. These bats have a characteristic that is otherwise unknown among mammals: the posterior tip of the last caudal vertebra (at the tip of the tail) is 'T' shaped.
The molars of nyterids are dilambdodont. The dental formula is 2/3, 1/1, 1/2, 3/3 = 32. Upper incisors are 2- or 3-lobed.
Nycterids have been found roosting alone, in pairs or in small family groups. This group has a great diversity of roosting habits, including caves, hollow logs, tree branches, tunnels, and human houses. They also sometimes roost in the burrows of other mammals such as hedgehogs, porcupines, and aardvarks.
The diet of slit-faced bats is diverse. Most species specialize on arthropods, and one species, Nycteris grandis, regularly catches and eats vertebrates. They forage close to surfaces including rock faces and bushes.
The supposed sister groups to the Nycteridae are the Megadermatidae and Rhinolophidae. No fossils are known.
References and literature cited:
Anderson, S. and J. K. Jones, Jr., 1984. Orders and Families of Recent Mammals of the World. John Wiley and Sons, New York. 686pp.
Feldhamer, G. A., L. C. Drickamer, S. H. Vessey, and J. F. Merritt. 1999. Mammalogy. Adaptation, Diversity, and Ecology. WCB McGraw-Hill, Boston. xii+563pp.
Fenton, M. B., P. Racey, and J.M. V. Rayner (eds.), 1987. Recent Advances in the Study of Bats. Cambridge University Press, Cambridge.
Hill, J. E. and J. D. Smith, 1992. Bats: A Natural History. University of Texas Press, Austin.
Nowak, Ronald M., 1994. Walker's Bats of the World. Johns Hopkins University Press, Baltimore.
Ransome, Roger, 1990. The Natural History of Hibernating Bats. Christopher Helm, London.
Vaughan, T. A., J. M. Ryan, N. J. Czaplewski. 2000. Mammalogy. Fourth Edition. Saunders College Publishing, Philadelphia. vii+565pp.
Wilson, D. E., and D. M. Reeder. 1993. Mammal Species of the World, A Taxonomic and Geographic Reference. 2nd edition. Smithsonian Institution Press, Washington. xviii+1206 pp.
Contributors
Bret Weinstein (author), University of Michigan. Phil Myers (author), Museum of Zoology, University of Michigan.
