Heptaxodontidaegiant hutias

This family, which consisted of 5 species in 4 genera, lived in the Greater Antilles plus Anguilla and St. Martins. All species are extinct, but it is likely that populatons of at least two genera, Amblyrhiza and Clidomys, coexisted with humans in the West Indies. The name "quemi" was the native name given to an animal described by early Spanish explorers. It was said to be slightly larger than a hutia ( Capromyidae) and was a source of food for natives. If the quemi was in fact a heptaxodontid, then this family became extinct soon after the Spanish conquest of the West Indies.

Heptaxodontids were medium-sized to very large rodents. The largest, Amblyrhiza, was nearly the size of a black bear. Their skulls resembled those of nutria ( Myocastoridae), but close relationship has also been suggested with the families Chinchillidae, Capromyidae, and Dinomyidae. Like nutrias, heptaxodontids had a massive rostrum, long paroccipital processes, large infraorbital canal with no accessory grove or foramen, sagittal crest often present, small bullae, and other characters. Their cheekteeth were strongly hypsodont, appearing to be made up of lamellar plates set at an angle to the long axis of the palate.

The fossil record of this family is restricted to the Pleistocene and Recent.

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.

Nowak, R. M. and J. L. Paradiso. 1983. Walker's mammals of the world. The Johns Hopkins University Press, Baltimore and London, pp 803-810.

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 (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, S. and J. K. Jones, Jr. (eds.). Orders and familes of mammals of the world. John Wiley and Sons, New York.


Phil Myers (author), Museum of Zoology, University of Michigan-Ann Arbor.


bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


having the capacity to move from one place to another.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


uses touch to communicate