The Sirenia, commonly referred to as sea cows or sirenians, are an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. The extant Sirenia comprise two distinct families: Dugongidae and Trichechidae with a total of four species. The Protosirenidae and Prorastomidae families are extinct. Sirenians are classified in the clade Paenungulata, alongside the elephants and the hyraxes, and evolved in the Eocene 50 million years ago (mya). The Dugongidae diverged from the Trichechidae in the late Eocene or early Oligocene.
The rock hyrax, also called dassie, Cape hyrax, rock rabbit, and coney, is a medium-sized terrestrial mammal native to Africa and the Middle East. Commonly referred to in South Africa as the dassie, it is one of the five living species of the order Hyracoidea, and the only one in the genus Procavia. Rock hyraxes weigh 4–5 kg (8.8–11.0 lb) and have short ears.
Mammalia is a class of animal within the phylum Chordata. Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is universally accepted; McKenna & Bell (1997) and Wilson & Reader (2005) provide useful recent compendiums. Many earlier ideas from Linnaeus et al. have been completely abandoned by modern taxonomists, among these are the idea that bats are related to birds or that humans represent a group outside of other living things. Competing ideas about the relationships of mammal orders do persist and are currently in development. Most significantly in recent years, cladistic thinking has led to an effort to ensure that all taxonomic designations represent monophyletic groups. The field has also seen a recent surge in interest and modification due to the results of molecular phylogenetics.
Procavia is a genus of hyraxes. The rock hyrax (P. capensis) is currently the only extant species belonging to this genus, though other species were recognized in the past, including P. habessinica and P. ruficeps, both now relegated to subspecific rank.
The tree hyrax or tree dassie is a small nocturnal mammal native to Africa. Distantly related to elephants and sea cows, it comprises the four species in the genus Dendrohyrax, one of only three genera in the family Procaviidae, which is the only living family within the order Hyracoidea.
The yellow-spotted rock hyrax or bush hyrax is a species of mammal in the family Procaviidae. It is found in Angola, Botswana, Burundi, the Democratic Republic of the Congo, southern Egypt, Eritrea, Ethiopia, Kenya, Malawi, Mozambique, Rwanda, Somalia, northern South Africa, South Sudan, Sudan, Tanzania, Uganda, Zambia, and Zimbabwe. Its natural habitats are dry savanna and rocky areas. Hyrax comes from the Greek word ὕραξ, or shrew-mouse.
Hyraxes, also called dassies, are small, stout, herbivorous mammals in the order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Modern hyraxes are typically between 30 and 70 cm in length and weigh between 2 and 5 kg. They are superficially similar to marmots, or over-large pikas, but are much more closely related to elephants and sirenians. Hyraxes have a life span from nine to 14 years. Both types of "rock" hyrax live on rock outcrops, including cliffs in Ethiopia and isolated granite outcrops called koppies in southern Africa.
