For extinct genera, see text Hyraxes (from Ancient Greek ὕραξ hýrax 'shrew-mouse'), also called dassies,[1][2] are small, stout, thickset, herbivorous mammals in the family Procaviidae within the order Hyracoidea.

[6] Hyraxes retain or have redeveloped a number of primitive mammalian characteristics; in particular, they have poorly developed internal temperature regulation,[7] for which they compensate by behavioural thermoregulation, such as huddling together and basking in the sun.

The permanent dental formula for hyraxes is 1.0.4.32.0.3-4.3[8] although sometimes stated as 1.1.4.32.1.4.3[9] because the deciduous canine teeth are occasionally retained into early adulthood.

[8] Although not ruminants, hyraxes have complex, multichambered stomachs that allow symbiotic bacteria to break down tough plant materials, but their overall ability to digest fibre is lower than that of the ungulates.

[15] The hyrax does not construct dens, but over the course of its lifetime rather seeks shelter in existing holes of great variety in size and configuration.

Their feet have rubbery pads with numerous sweat glands, which may help the animal maintain its grip when quickly moving up steep, rocky surfaces.

[21] Hyraxes share several unusual characteristics with mammalian orders Proboscidea (elephants and their extinct relatives) and Sirenia (manatees and dugongs), which have resulted in their all being placed in the taxon Paenungulata.

Male hyraxes lack a scrotum and their testicles remain tucked up in their abdominal cavity next to the kidneys,[22][23] as do those of elephants, manatees, and dugongs.

[28] For many millions of years, hyraxes, proboscideans, and other afrotherian mammals were the primary terrestrial herbivores in Africa, just as odd-toed ungulates were in North America.

Nevertheless, the order remained widespread and diverse as late as the end of the Pliocene (about two million years ago) with representatives throughout most of Africa, Europe, and Asia.

While hyraxes are closely related, they form a taxonomic outgroup to the assemblage of elephants, sirenians, and the extinct orders Embrithopoda and Desmostylia.

[35] The extinct meridiungulate family Archaeohyracidae, consisting of seven genera of notoungulate mammals known from the Paleocene through the Oligocene of South America,[36] is a group unrelated to the true hyraxes.

†Seggeurius †Microhyrax †Bunohyrax †Pachyhyrax †Thyrohyrax †Selenohyrax †Saghatherium †Titanohyrax †Antilohyrax †Megalohyrax †Geniohyus (elephants, mammoths, and mastodons) (horses, asses, and zebras; rhinos; and tapirs) †Phenacodontidae[C] Hyracoidea[40][41] In the 2000s, taxonomists reduced the number of recognized species of hyraxes.

[54] Roman coins struck in the region from the reign of Hadrian show a female figure with a rabbit at her feet,[55] and Strabo called it the "land of the 'rabbits'".