Hippopotamus gorgops

Extinct species of mammal

Hippopotamus gorgops is an extinct species of Hippopotamus known from remains found in Northern and Eastern Africa as well as the Levant. It first appeared during the late Pliocene Early Pleistocene, and became extinct during the early Middle Pleistocene. It is closely related and possibly ancestral to the European species Hippopotamus antiquus.

Hippopotamus gorgops is known from remains found across Northern and Eastern Africa, spanning from the Late Pliocene Early Pleistocene boundary to the early Middle Pleistocene. Remains assigned to H. gorgops alongside the species H. behemoth are known from the Ubeidiya locality in Israel, dating to approximately 1.6 million years ago, with some authors suggesting that H. behemoth is actually a synonym of H. gorgops, given their similar morphology.

H. gorgops grew substantially larger than the living hippopotamus (H. amphibius), with an estimated body mass of over In comparison to H. amphibius, the orbits and nasal openings are elevated higher above the rest of the skull, with the temporal fossa being shorter, resulting in the distance between the orbits and occiput being shorter. This likely meant a more forward attachment of the temporal muscles. In life H. gorgops would have likely greatly resembled H. amphibius.

Isotopic analysis of specimens from the Lake Turkana Basin suggests a high consumption of C4 plants. For specimens from Olduvai Gorge in Tanzania, dental microwear suggests a mixed feeding diet (including both browse and grass), while mesowear suggests a largely grazing diet. The elevated orbits have led to suggestions of a more aquatic lifestyle than H. amphibius, though its robust limbs indicate that it was probably capable of moving efficiently on land, like H. amphibius. These include El Kherba in Algeria, dating to around 1.8 million years ago (mya), It is unlikely that healthy adult individuals were hunted, as with living hippopotamuses, they were likely dangerous.