ABSTRACT. The complete dentition of the common ancestor of Australopithecus and Homo, intermediate between that of a pongid and a hominid, is virtually unknown. The maxillary dentition (P3-M2) of Ramapithecus brevirostris L~wIs, 1934, a pongid from the Early Pliocene, and that of hominids from the Late Pliocene and Plio/Pleistocene is known. Since R. brevirostris is probably ancestral to the hominids, a model of intermediate maxillary dentition (P3-M2) is extrapolated and described. The model represents a hypothetical protohominid dentition. It does not conform with the teeth of Australopithecus, but shows greater morphological affinity to hominine dentition and to 5 myo hominids. The Homo lineage, therefore, may go back to the Middle Pliocene. According to the normal sequence of evolution, it is most unlikely that Australopithecus gave rise to Homo, but much more probable that a very early, generalized Homo evolved into an advanced, specialized Australopithecus.