hippopotamus

about africa after amphibius ancestor ancient and are around artiodactyl belonging cetaceans closest comes common date despite diverged earliest elephant etc even extant family for fossils from genus greek heaviest herbivorous hippo hippopotamidae hippopotamus hippos horse kenyapotamus known land large largest living mammal million mostly name one only other physical pigs porpoises pygmy relatives resemblance rhinoceros river saharan species split sub terrestrial the their they third toed two type ungulates whales which years