The genus Orycteropus includes just a single living species, the Aardvark (Orycteropus afer). Aardvarks were at one time thought to be closely related to anteaters, tree sloths, armadillos, and pangolins. It eventually became clear, however, that the similarities on which these associations were based are the result of convergent evolution independently shaping the morphology (body form) of these different animals for similar functions, such as feeding on ants and termites. As their distinctiveness was recognized, Aardvarks were eventually moved to their own genus (Orycteropus), then their own family (Orycteropodidae), and eventually, in the early 20th century, their own order (Tubulidentata).
Molecular phylogenetic studies have revealed that Aardvarks belong to the broad mammal clade known as Afrotheria, a group that includes elephants, hyraxes, sirenians, sengis, and tenrecs and golden moles.
Aardvarks typically swallow their food without chewing, but the stomach has a thick muscular wall that helps to crush swallowed food. The tongue is long and tubular and can be extended to twice its "resting" length, allowing it to reach far into ant tunnels. The powerfully built body is well suited to digging, as are the long, sharp claws on the front feet.
Aardvarks are widespread in sub-Saharan Africa in a range of habitats from semi-arid deserts such as the Kalahari and Karoo regions and throughout savanna regions to (at least to some degree) the rainforests of West Africa. The key requirements for Aardvark habitat are an adequate supply of ants and termites and soil amenable to burrowing. Aardvarks occur at elevations as high as 3200 m in the Bale Mountains of Ethiopia and do not appear to be limited by the occurrence of water. Unoccupied Aardvark burrows are often used by other animals.
Aardvarks are solitary and nocturnal and spend most of their time eating or sleeping. Because of their habits, Aardvarks rarely interact with humans. Farmers sometimes kill them because their deep burrows can injure livestock or damage farm equipment and Aardvarks sometimes burrow into the earth walls of water storage dams, causing leaks. In Central and West Africa, Aardvarks are killed for the bush meat trade. They are also killed for curios and for charms in traditional medicine. Despite these threats, populations are believed to be stable at least in southern Africa, where the bushmeat trade is not a big factor.
(Taylor 2011 and references therein)
Three species are recognized: