Ardipithecus ramidus and the Paleobiology of Early Hominids

• DOI: 10.1126/science.1175802
• Publication Date: 2009-10-01T22:46:39Z
• Authors: Tim D. White; Berhane Asfaw; Yonas Beyene; Yohannes Haile-Se...; C. Owen Lovejoy; Gen Suwa; Giday WoldeGabriel
• Keywords: Australopithecus; Hominidae; Arboreal locomotion; Homo sapiens; Paleobiology; Living fossil; Postcrania; Lineage (genetic)

Hominid fossils predating the emergence of Australopithecus have been sparse and fragmentary. The evolution our lineage after last common ancestor we shared with chimpanzees has therefore remained unclear. Ardipithecus ramidus, recovered in ecologically temporally resolved contexts Ethiopia's Afar Rift, now illuminates earlier hominid paleobiology aspects extant African ape evolution. More than 110 specimens from 4.4-million-year-old sediments include a partial skeleton much skull, hands, feet, limbs, pelvis. This combined arboreal palmigrade clambering careful climbing form terrestrial bipedality more primitive that Australopithecus. Ar. ramidus had reduced canine/premolar complex little-derived cranial morphology consumed predominantly C3 plant-based diet (plants using photosynthetic pathway). Its ecological habitat appears to largely woodland-focused. lacks any characters typical suspension, vertical climbing, or knuckle-walking. indicates despite genetic similarities living humans chimpanzees, probably differed substantially ape. Hominids apes each become highly specialized through very different evolutionary pathways. evidence also origins orthogrady, bipedality, ecology, diet, social behavior earliest Hominidae helps define basal adaptation, thereby accentuating derived nature