Projection of Nasal Bones above Frontomaxillary Suture

The morphology of the nasal bones has often been considered of phyloge-netic significance (Robinson, 1954; Tobias, 1967; Olsen, 1978, 1985; Rak, 1983). This is emphasized because the nasal region and its relationship to nasion and glabella are formed early in ontogeny, within late fetal growth (Olson, 1985); thus, it is less likely influenced by functional considerations. First, the nasal bones extend superior to the frontomaxillary suture, resulting in a tapering of the nasal bones above the suture (= 0), as observed in Dryopithecus (Kordos & Begun, 1997), Pongo, Gorilla, Pan, and Australopithecus. Next, they are defined by the projection of the nasal bones above the frontomaxillary suture, widening laterally as they pass the suture line (= 1), as observed in Praeanthropus and species within Paranthropus. The last condition is defined by the nasal bone not projecting above the frontomaxillary suture (= 2), observed in K. rudolfensis, H. ergaster, H. habilis, and H. sapiens (Strait & Grine, 2001).

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