Hyracoidea

Article By:

Rasmussen, D. Tab Department of Anthropology, Washington University, Saint Louis, Missouri.

Last reviewed:January 2020

DOI:https://doi.org/10.1036/1097-8542.334800

An order of mammals closely related to elephants. Hyracoids were a diverse and successful group of mammals in Africa during the Eocene and Oligocene epochs (early part of the Age of Mammals, 55 to 34 million years ago), and they are still represented by a few living species. The early hyracoids ranged from animals as small as rabbits to ones as large as modern Sumatran rhinoceroses. The fossil skeletons of the early hyracoids indicate that some species were active runners and leapers, while others were heavy, piglike quadrupeds. Their teeth suggest herbivorous diets, ranging from fibrous leaves in some species to pulpy fruits and roots in others. Hyracoids originated in Africa but later extended their range into Europe and Asia, eventually attaining a distribution encompassed by China, Spain, and South Africa. In contrast to the early diversity of the order, the only living species are a few small-bodied animals (1.5–5.5 kg or 3.3–12 lb) that inhabit forests, scrubby brushlands, and rocky deserts in Africa and the Middle East. Hyracoidea represents a classic case of a spectacular adaptive radiation on an isolated continent, now reduced to a few remnant living taxa. See also: Eocene; Oligocene

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