Evolution and systematics

The native rodents of the West Indies, living and extinct, are an extraordinarily diverse group. They are sorted by tax-onomists into four families, 15 genera, and about 60 species, including family Heptaxodontidae, with four genera and five species.

Only Pleistocene and Recent (post-Pleistocene to present) fossils and subfossils are known for the Heptaxodontidae, most of these recovered from caves. The Heptaxodontidae most likely arose in isolation on the islands of the Antilles from an ancestral species that rafted from the mainlands of the Americas. Taxonomists have tried to link the family with the families Myocastoridae (nutria), Chinchillidae (chinchillas and viscachas), Capromyidae (hutias), and Dinomyidae (pacaranas and related species).

At least one genus, Quemisia, may still have been extant when Native Americans first occupied the islands, in 7000 B.C., while Clidomys and Amblyrhiza apparently became extinct during the Pleistocene Epoch before the arrival of humans on the Antilles.

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