Doctoral Dissertation Improvement: Plio-Pleistocene Hominin Teeth from Dmanisi, Georgia

Suny At Binghamton, Binghamton NY

Investigators

Abstract

The identity of the first human species to disperse out of the African homeland and the timing of this event remain highly controversial. The problem lies in the fact that few sites of critical age have yielded both significant hominin remains and artifacts from geologic contexts which can be reliably dated. The Dmanisi site in the Republic of Georgia challenges the doubts raised in respect to other, potentially early sites in China and Java, and adds to our understanding of the first hominin dispersals from Africa. Dmanisi, which dates to the earliest Pleistocene (1.77 mya), is a site rich in paleontological and archaeological evidence, and it has produced the largest sample of early Homo remains from a single level at a locality anywhere in the world. In addition, the fossils occupy an intermediate position, both morphologically and temporally, between earliest Homo and later Homo erectus. Many studies have demonstrated that information about tooth crown and root size together with observations of morphological traits can contribute significantly to taxonomic, phylogenetic, and functional analyses of Plio-Pleistocene hominins. This study focuses on the continually growing hominin dental sample from the site of Dmanisi. The Dmanisi dental sample now includes teeth from three mandibles, two crania, and a number of isolated finds, which together represent a minimum of 3 individuals. Many of the specimens are currently unpublished. All will be documented through description and measurement, aided by imaging techniques such as digital photography and radiography. Patterns of variation will then be analyzed to determine if the metric and morphologic differences among the teeth likely reflect interspecific or intraspecific variation, including differences between the sexes. The Dmanisi dental remains will be compared with other early Homo erectus (=ergaster) teeth from East Africa and Southeast Asia, and to specimens of earlier Homo from the Turkana basin and Olduvai Gorge. This analysis will document the range of dental variation for Homo habilis and early Homo erectus, establish the position of the Dmanisi specimens within that range, and help to identify any probable phylogenetic (ancestor-descendant) relationships between the Dmanisi sample and the other hominin groups. This quantitative work on dentition will contribute to a better understanding of intra- and inter-populational hominin variation and the taxonomy of the earliest members of the genus Homo. This research will also provide a unique dataset with which to evaluate scenarios concerning the initial migration of hominins from the African homeland and the paleobiology of the earliest Eurasians. The broader impact of project funding is that it will permit the Co-PI to travel to Georgia for analysis of the dental material and allow for collaboration with both Georgian and US scientists. The proposed research also offers outstanding educational opportunities in laboratory data collection and analysis, to both the Co-PI and others involved in the project.