Fossils from Northafrican elephant has been found in Africa, where they developed in the middle Pliocene. The oldest known zoological collection in the world was revealed during excavations at Nekhen in 2009 of Hierakonpolis zoo in Egypt, a menagerie that dates to c. 3500 BC. The animals included Northafrican elephant hippopotami, hartebeest, baboons, and African wildcats.