See below Afrotheria (/æfroʊˈθɪəriə/ from Latin Afro- "of Africa" + theria "wild beast") is a superorder of placental mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephant shrews (also known as sengis), otter shrews, tenrecs, aardvarks, hyraxes, elephants, sea cows, and several extinct clades.
found on other continents throughout the Cenozoic, and proboscideans (elephants and their relatives) filled the roles of large herbivores such as hippos, camels, rhinos, and tapirs.
The sirenians developed aquatic body plans and started spreading to other parts of the world by water (evolving convergently with the other groups of marine mammals such as cetaceans and pinnipeds).
On the anatomical side, features shared by most, if not all, afrotheres include high vertebral counts,[8] aspects of placental membrane formation,[17] the shape of the ankle bones,[6][7] the relatively late eruption of the permanent dentition,[18] and undescended testicles remaining in the body near the kidneys.
[20] Studies of genomic data, including millions of aligned nucleotides sampled for a growing number of placental mammals, also support Afrotheria as a clade.
[21][22] Additionally, there might be some dental synapomorphies uniting afroinsectiphilians, if not afrotheres as a whole: p4 talonid and trigonid of similar breadth, a prominent p4 hypoconid, presence of a P4 metacone and absence of parastyles on M1–2.
One reconstruction, which applies the molecular clock, proposes that the oldest split occurred between Afrotheria and the other two some 105 million years ago in the mid-Cretaceous, when the African continent was separated from other major land masses.
[29] A 2021 morphological study also proposed to render Meridiungulata polyphyletic and recognise most of its clades as part of a group called Sudamericungulata, closely related to hyraxes, while Litopterna remains a sister taxon to Perissodactyla.
[14][15] Procaviidae Trichechidae Dugongidae Elephantidae Orycteropodidae Macroscelididae Chrysochloridae Potamogalidae Tenrecidae Many extant members of Afrotheria appear to have a high risk of extinction (perhaps related to the large size of many).