The earliest proof that humans were involved with hippos comes from butchery cut marks on hippo bones at Bouri Formation from around 160,000 years ago. Later rock paintings and engravings showing hippos being hunted. They have been found in the mountains of the central Sahara from 4,000–5,000 years ago near Djanet. Ancient Egyptians also knew much about hippos. They knew the hippo was a fierce, wild animal that lived in the Nile. In Egyptian mythology, Tawaret, a goddess of protection in pregnancy and childbirth, had the head of a hippo. This was because ancient Egyptians saw how protective female hippopotami could be about their young.