Paenungulata is a taxon that groups three extant mammal orders: Proboscidea (including elephants), Sirenia (sea cows, including dugongs and manatees), and Hyracoidea (hyraxes, such as the African Rock Hyrax, Procavia habessinica). At least two more orders are known only as fossils, namely Embrithopoda and Desmostylia. Both of these extinct orders were as unique in their ways as the surviving orders. Embrithopods were rhinoceros-like herbivorous mammals with plantigrade feet, and desmostylians were hippopotamus-like amphibious animals. Their walking posture and diet have been the subject of speculation, but tooth wear indicates that desmostylians browsed on terrestrial plants and had a posture similar to other large hoofed mammals.
- 1 Kleinschmidt, Traute; Czelusniak, John; Goodman, Morris; Braunitzer, Gerhard (1986). "Paenungulata: A Comparison of the Hemoglobin Sequences from Elephant, Hyrax, and Manatee". Mol. Biol. Evol. 3 (5): 427–435. PMID 3444412. Retrieved 2010-07-24.