By Phil Myers
About 20 species have been described; these are placed in 8 genera. About half of species, however, are probably extinct. Capromyids are found on the islands of the West Indies, reaching their greatest diversity on Cuba.
These rodents range in size from rat-like to large, with the largest weighing up to around 7 kg. They resemble nutrias ( Myocastoridae) and are sometimes placed in that family. Their bodies are stout and strong, their heads large, and their tails vary from practically nonexistent to long and prehensile. The legs are short, and the feet are plantigrade and have 5 toes. The claws are strong and curved in most species. The pelage of capromyids is thick but varies considerably in color and texture.
The 
skulls of capromyids resemble those of nutrias. They are hystricomorphous and hystricognathous, strongly built and heavily ridged. The rostrum is short; a sagittal crest is often present. The zygomatic arches are broad and robust. The infraorbital canal is large and without an accessory groove or canal for the passage of nerves to the face. The jugal does not contact the lacrimal. The bullae are not enlarged, and the paroccipital processes are intermediate to long in length. On the lower jaw, the angular and coronoid processes vary considerably in size, but the coronoid process is usually prominent.
The dental formula of members of this family is 1/1, 0/0, 1/1, 3/3 =20, but the deciduous premolars are not shed. The cheekteeth of capromyids are similar to those of nutria. They are hypsodont and flatcrowned, with re-entrant folds that vary among species in number and tendency to be isolated as islands.
Some capromyids are terrestrial, others are partly arboreal. Diets vary among species; most feed primarily on vegetation, but some include invertebrates and even lizards when they can get them. They do not dig burrows, but usually reside in hollow trees or rock crevices. A few species are common to the point of being agricultural pests, but many are endangered or their status is unknown.
References and literature cited:
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.
Lawlor, Timothy. 1979. Handbook to the orders and families of living mammals. Mad River Press, Eureka, California.
Macdonald, David. 1984. The encyclopedia of mammals. Facts on File Publications, New York.
Nowak, Ronald M. and John L. Paradiso. 1983. Walker's mammals of the world. The Johns Hopkins University Press, Baltimore and London, pp 803-810.
Vaughan, T. A. 1986. Mammalogy. Third Edition. Saunders College Publishing, Fort Worth. vii+576 pp.
Vaughan, T. A., J. M. Ryan, N. J. Czaplewski. 2000. Mammalogy. Fourth Edition. Saunders College Publishing, Philadelphia. vii+565pp.
Wilson, Don E. and DeeAnn M. Reeder (eds.). 1993. Mammal species of the world: A taxonomic and geographic reference, 2nd ed.. Smithsonian Institution Press, Washington and London.
Woods, C. A. 1984. Hystricognath rodents. Pp. 389-446 in Anderson, Sydney and J. Know Jones, Jr. (eds.). Orders and familes of mammals of the world. John Wiley and Sons, New York.
Contributors
Phil Myers (author), Museum of Zoology, University of Michigan.
