species: from Anthracotherium and Elomeryx to the Miocene species Merycopotamus and Libycosaurus and finally the very latest anthracotheres in the Pliocene. These groups lived across Eurasia and Africa. The discovery of Epirigenys in East Africa, which was likely a descent of Asian anthracotheres and a sister taxon to Hippopotamidae suggests that hippo ancestors likely entered Africa from Asia around . An early hippopotamid is the genus Kenyapotamus, which lived in Africa from 15 to . Hippopotamid species would spread across Africa and Eurasia, including the modern pygmy hippo. From 7.5 to , a possible ancestor to the modern hippo, Archaeopotamus, lived in Africa and the Middle East. Extinct species Three species of Malagasy hippopotamus became extinct during the Holocene on Madagascar, the last of them within the past 1,000 years. The Malagasy hippos were smaller than the modern hippo, a likely result of the process of insular dwarfism. Fossil evidence indicates many Malagasy hippos were hunted by humans, a factor in their eventual extinction. Isolated individual Malagasy hippos may have survived in remote pockets; in 1976, villagers described a living animal called the kilopilopitsofy, which may have been a Malagasy hippo. An extinct species, Hippopotamus antiquus, ranged throughout Europe, extending as far north as Britain during the Early and Middle Pleistocene epochs, before being replaced by the modern H. amphibius during the latter part of the Middle Pleistocene. The Pleistocene also saw a number of dwarf species evolve on several Mediterranean islands, including Crete (Hippopotamus creutzburgi), Cyprus (the Cyprus dwarf hippopotamus, Hippopotamus minor), Malta (Hippopotamus melitensis), and Sicily (Hippopotamus pentlandi). Of these, the Cyprus dwarf hippo survived until the end of the Pleistocene or early Holocene. Evidence from the archaeological site Aetokremnos continues to cause debate on whether or not the species was driven to extinction, or even encountered, by man. Across Eurasia, the hippopotamus became extinct between 50,000 and 16,000 years ago. Characteristics and adaptations The hippopotamus is a megaherbivore and is exceeded in size among land animals only by elephants and some rhinoceros species. The mean adult weight is around for bulls and for cows. Exceptionally large males have been recorded reaching . Male hippos appear to continue growing throughout their lives, while females reach maximum weight at around age 25. Hippos measure long, including a tail of about in length and tall at the shoulder, with males and females ranging and tall at the shoulder respectively. The