Fig. 1.

Phylogeny of the genera belonging to the Hominid family. Four different genera are proposed, corresponding to four kinds of adaptation. The genus Praeanthropus (formerly named Australopithecus) evolved incipient bipedalism on the ground of tropical forests. The genus Ardipithecus evolved a dietary adaptation that developed thin molar enamel, similar to that of the African great apes. The genus Australopithecus (formerly also named Paranthropus) exploited hard vegetal resources of the savanna by developing a robust masticatory apparatus. The genus Homo retained gracile maxillae and dentition and later initiated the development of larger crania and cultural adaptation to the savanna by means of lithic industries. The proposed names follow the rules of taxonomy, favoring the names given initially, when the first taxon of the genus was established. The phylogenetic location and taxonomic classification of Sahelanthropus are uncertain. Pairs of Homo taxa separated by a slash represent closely related (or, according to some authors, the same) species. An asterisk marks each species germinalis, i.e., originating a genus.