Paenungulata

views updated

Paenungulata (infraclass Eutheria, cohort Ferungulata) A superorder that comprises herbivorous animals which diverged from the primitive Palaeocene ungulate stock to become ‘subungulates’ or ‘near ungulates’. The superorder includes the orders Hyracoidea (hyraxes), Proboscidea (elephants, their ancestors, and other elephant-like forms), Pantodonta, Dinocerata, Pyrotheria, Embrithopoda, and Sirenia (seacows or mermaids). It has been proposed recently, however, that the Hyracoidea belong to the Mesaxonia; some consider the Paenungulata to be an entirely artificial group and combine only the Proboscidea and Sirenia into a superorder, Tethytheria. In all of them the ulna and fibula are complete, and the upper bones of the limbs are long. The digits bear nails but, in most cases, not hoofs. Molars are specialized for grinding, and the incisors and canines are often reduced and modified to form tusks.