Ardipithecus

Ardipithecus is a very early hominid genus, which lived during the late Neogene.
Two species are known: "A. kadabba", dated to about 5.6 million years ago (late Miocene), and "A. ramidus", which lived about 4.4 million years ago during the early Pliocene. 
Because this genus shares several traits with the African great ape genera ("Pan" and "Gorilla"), some place it on the that branch rather than human branch. 
Most consider it a proto-human because of a likeness in teeth with "Australopithecus". "Ardipithecus" had bipedalism and reduced canines, like the Australopithecines.