Fossil Skulls from Dmanisi: A Paleodeme Representing Earliest Homo in Eurasia

Abstract

The Plio-Pleistocene site of Dmanisi has yielded much evidence bearing on the morphology and behavior of the earliest hominins from western Eurasia. Human remains, animal bones and stone artifacts were deposited at Dmanisi during a brief interval following the close of the Olduvai Subchron (1.77 million years ago). The hominin fossils now include an adult braincase (D2280), the partial skull of a young adult (D2282/D211), a large mandible (D2600), a small subadult skull (D2700/D2735), an edentulous cranium with lower jaw (D3444/D3900), and postcranial bones attributed to several individuals. The crania have capacities ranging from 600 to 775 cm3. Supraorbital tori and other vault superstructures are only moderately developed. Although there is variation related to ontogenetic age and sex dimorphism, it is appropriate to group the Dmanisi individuals together. Most probably, all of the hominins are sampled from one paleodeme. This population resembles Homo habilis in brain volume and some aspects of craniofacial morphology, but many of these features can be interpreted as symplesiomorphies. Other discrete characters and measurements suggest that the Dmanisi skulls are best placed with H. erectus. There are numerous similarities to individuals from the Turkana Basin in Kenya, but a few features link Dmanisi to Sangiran in Java. This evidence can be read to support an early dispersal of H. erectus from Africa to Eurasia. However, an alternative hypothesis must also be considered. Morphological comparisons of the fossils and findings from geochronology are consistent with the view that H. erectus evolved in Asia. Only later did representatives of this species disperse from western Asia to Africa and eastward toward Java and China.