Homo habilis ( /ˈhoʊmoʊ ˈhæbɨlɪs/, "handy-man") is a species of the genus Homo, which lived from approximately 2.33 to 1.4 million years ago, during the Gelasian Pleistocene period. The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. Homo habilis (or possibly H. rudolfensis) was the earliest known species of the genus Homo until May 2010, when H. gautengensis was proposed by Darren Curnoe, a species theorized to be even older than H. habilis.
In its appearance and morphology, H. habilis is the least similar to modern humans of all species in the genus (except possibly H. rudolfensis). H. habilis was short and had disproportionately long arms compared to modern humans; however, it had a less protruding face than the australopithecines from which it is thought to have descended. H. habilis had a cranial capacity slightly less than half of the size of modern humans. Despite the ape-like morphology of the bodies, H. habilis remains are often accompanied by primitive stone tools (e.g. Olduvai Gorge, Tanzania and Lake Turkana, Kenya).
Homo habilis has often been thought to be the ancestor of the more gracile and sophisticated Homo ergaster, which in turn gave rise to the more human-appearing species, Homo erectus. Debates continue over whether H. habilis is a direct human ancestor, and whether all of the known fossils are properly attributed to the species. Some paleoanthropologists regard the taxon as invalid, made up of fossil specimens of Australopithecus and Homo. In 2007, new findings suggested that H. habilis and H. erectus coexisted and may be separate lineages from a common ancestor instead of H. erectus being descended from H. habilis.