Hippopotamus gorgops

Hippopotamus gorgops ("Gorgon-eyed river horse") is an extinct species of hippopotamus. It first appeared in Africa during the late Miocene, and eventually migrated into Europe during the early Pliocene (where its fossils were first discovered). It became extinct prior to the Ice Age.

With a length of 4.3 metres (14 ft) and a shoulder height of 2.1 metres (6.9 ft) and with a weight of 3,900 kilograms (8,600 lb) H. gorgops was much larger than its living relative, H. amphibius. Another feature setting it apart from H. amphibius was the placement of its eyes. Modern hippos have eyes placed high on the skull, but H. gorgops had eyestalk-like orbits extruding above its skull, making it even easier for the creature to see its surroundings while (almost) fully under water.