The familiar Nile or common hippo, Hippopotamus amphibious, is more abundant and can be found in aquatic habitats across sub-Saharan Africa. Hippos and whales had a common ancestor that lived about 55 million years ago, after which hippos and cetaceans branched out. African fishes including cichlids and barbels nibble the dead skin, algae, and parasites on the hippo’s skin and inside their mouths. Archaeologists investigating a 700,000-year-old human habitation site in Ethiopia found numerous hippo bones that bore marks from butchering tools. Ancient Egyptians hunted hippos for their meat, skin, and teeth, and carved spiritually protective designs into their tusk-like canines.