Archaeopotamus is an extinct genus of hippopotamidae that lived between 7.5 and 1.8 million years ago in Africa and the Middle East. The genus was described in 2005 to encompass species of hippos that were previously grouped in Hexaprotodon. For other uses of the word, please see Genus (disambiguation). ... Genera Hippopotamus Phanourios Hexaprotodon Archaeopotamus Choeropsis Saotherium Hippopotami (colloquially also Hippopotamuses) are the members of the family Hippopotamidae. ... A world map showing the continent of Africa Africa is the worlds second-largest and second most-populous continent, after Asia. ... A map showing countries commonly considered to be part of the Middle East The Middle East is a region comprising the lands around the southern and eastern parts of the Mediterranean Sea, a territory that extends from the eastern Mediterranean Sea to the Persian Gulf. ... Binomial name Choeropsis liberiensis (Morton, 1849) Subspecies The Pygmy Hippopotamus (Choeropsis liberiensis) is a large mammal native to the forests and swamps of western Africa (the species name, meaning of Liberia, reflects this). ...

The word Archaeopotamus means "the ancient of the river." Of all identified hippos, only Kenyapotamus is older. The Kenyapotamus, however, is only known from partial fossils. Archaeopotamus is the oldest well-identified hippo.^[1] Binomial name Kenyapotamus coryndoni and Kenyapotamus ternani Pickford, 1983 Kenyapotamus is an extinct ancestor of the modern Hippopotamus which lived in Africa roughly 16 million to 8 million years ago during the Miocene epoch. ...

Characteristics

Many prehistoric hippo fossils are known primarily through fossils of the lower jaw. The Archaeopotamus, like Hexaprotodon, has three pairs of incisors. Unlike other Hexaprotodons, Archaeopotamus has a highly elongate mandibular symphysis. The informal name "narrow muzzled hippos" has been suggested for this genus. The mandible (from Latin mandibÅ­la, jawbone) or inferior maxillary bone is, together with the maxilla, the largest and strongest bone of the face. ... The external surface of the mandible is marked in the median line by a faint ridge, indicating the Symphysis menti or line of junction of the two pieces of which the bone is composed at an early period of life. ...

A. lothagamensis

A. lothagamensis is a species whose fossils were discovered at Lothagam, a site southwest of Lake Turkana in Kenya and first described in 2000. When first described, the species was classified as Hexaprotodon lothagamensis, although the significant morphological differences between other Hexaprotodon species, were noted.^[2] View over Lake Turkana Lake Turkana, formerly known as Lake Rudolf, is a lake in the Great Rift Valley in Kenya (although the far northern end of the lake crosses into Ethiopia), which covers a surface area of 6405 km² (2473 mi²), making it the worlds largest permanent desert...

A. lothagamensis was smaller than the modern hippopotamus and also smaller than A. harvardi and with a more slender skeleton. It was, however, significantly larger than the modern pygmy hippopotamus. Binomial name Hippopotamus amphibius Linnaeus, 1758 Range map The hippopotamus (Hippopotamus amphibius), from the Greek ‘ιπποπόταμος (hippopotamos, hippos meaning horse and potamos meaning river), is a large, mostly plant-eating African mammal, one of only two extant in the family Hippopotamidae. ... Binomial name Choeropsis liberiensis (Morton, 1849) The Pygmy Hippopotamus (Choeropsis liberiensis) is a large mammal native to the forests and swamps of western Africa (the species name, meaning of Liberia, reflects this). ...

A. harvardi

A. harvardi is a species of hippo first described in 1977, originally as Hexaprotodon harvardi.^[3] Although the proportions of A. harvardi and A. lothagamensis are similar, the former species is significantly smaller. Femurs of A. harvardi are approximately the same size as those of the modern hippopotamus.

Another group of fossils, originally described as Hexaprotodon sahabiensis or the Abu Dhabi Hippopotamus, are now considered to belong to A. harvardi or A. lothagamensis. The fossil record for A. harvardi is more extensive than for other Archaeopotamus.^[2][1]

A. harvardi is believed to have had a more riparian lifestyle than A. lothagamensis. A riparian zone schematic from the Everglades. ...

Distribution

Fossils of Archaeopotamus have been unearthed near Lake Turkana, Kenya; near Lake Victoria in Kenya and in Abu Dhabi and thus likely ranged across East Africa and the Arabian Peninsula. View over Lake Turkana Lake Turkana, formerly known as Lake Rudolf, is a lake in the Great Rift Valley in Kenya (although the far northern end of the lake crosses into Ethiopia), which covers a surface area of 6405 km² (2473 mi²), making it the worlds largest permanent desert... Lake Victoria and the Great Rift Valley Lake Victoria height variation The lake as seen from space, looking west, with other members of the African Great Lakes forming an arc in the middle distance. ... Abu Dhabi or Abu Zaby (Arabic language: أبوظبي) is the largest of the seven emirates that comprise the United Arab Emirates and was also the largest of the former Trucial States. ...  Eastern Africa (UN subregion)  East African Community  Central African Federation (defunct)  geographic, including above East Africa or Eastern Africa is the easternmost region of the African continent, variably defined by geography or geopolitics. ... The Arabian Peninsula Emirets towers in United Arab Emirates; the eastern part of Arabian Penisula The Arabian Peninsula (in Arabic: شبه الجزيرة العربية, or جزيرة العرب) is a peninsula in Southwest Asia at the junction of Africa and Asia consisting mainly of desert. ...

Evolution

The immediate ancestor of Archaeopotamus is unknown. Whether or not Archaeopotamus is descended from Kenyapotamus cannot be determined from the few fossils available. Although Archaeopotamus is more primitive than any Hippopotamus, they are likely a sister group of both Hippopotamuses and Hexaprotodons. Binomial name Kenyapotamus coryndoni and Kenyapotamus ternani Pickford, 1983 Kenyapotamus is an extinct ancestor of the modern Hippopotamus which lived in Africa roughly 16 million to 8 million years ago during the Miocene epoch. ...

Fossils similar to Archaeopotamus have been dated to as recently as about 2 million years ago, the end of the Pliocene epoch. These fossils are significantly different from Hippopotamuses and Hexaprotodons of the same time. The Pliocene epoch (spelled Pleiocene in some older texts) is the period in the geologic timescale that extends from 5. ...

References