Dmanisi Skulls

          The article “A Complete Skull from Dmanisi, Georgia, and the Evolution of Early Homo” describes archaeological finds from a site in central Asia, detailing their relevance to early hominin evolution and potentially challenging prior assumptions about human migration and species distinctions. Excavation began on the Dmanisi site in 1999, with researchers first finding assorted fauna fossils, then stone tools, and finally hominid remains. These hominid fossils have been linked to H. habilis and H. erectus in Africa and H. erectus in East Asia. The hominid remains in Dmanisi are especially important because they have been dated to 1.8 million years ago, and thus represent the earliest hominid finds outside of Africa, casting doubt on previous knowledge as to when human ancestors first traveled to other continents. One of the main focuses of the article is a particular fossil known as skull 5, which is the first and only completely preserved adult hominid skull found from the early Pleistocene. This fossil is important because it provides evidence of the orientation of the face relative to the brain case, and serves as an intact sample of fully developed adult cranial morphology, which was previously unavailable due to earlier finds being either incomplete, damaged, or juvenile skulls. Skull 5 is described as having a small brain case, a large, prognathic face, and very robust features. Skull 5 in the context of the 4 other sets of remains, also shows distinct morphologic variations, despite almost certainly being of the same species, since they were all found in the same general location and dated to approximately the same time. The notable anatomical differences in the shape of the skulls led researchers to measure the morphological variation between the Dmanisi finds and compare it to the variation found in extant ape species, like chimpanzees and bonobos. This analysis led them to conclude that the variation in the Dmanisi fossils is well within the range of normal variation within a species population. The article went on to say that such a conclusion raises questions about whether previous finds from elsewhere in Asia and Africa, which were categorized as separate and distinct species, are in fact merely part of a single widespread Homo lineage.