Dmanisi in brief
Dmanisi sits on a promontory above a river valley in southern Georgia, about 90 kilometres southwest of the capital, Tbilisi. On top lie the remains of a medieval town on the old trade routes of the Caucasus. Beneath it, in layers of volcanic and river sediment about 1.85 to 1.78 million years old, lie the bones of early humans, stone tools, and fossils of many animals.
The people of Dmanisi lived at the edge of Africa and Asia, soon after humans first left Africa, and they are the best view we have of those early travellers.
Discovery
In the 1980s Georgian archaeologists were digging the medieval town. In 1983 a team led by Abesalom Vekua found the tooth of an extinct rhinoceros in a pit that had been dug by medieval builders, which showed that much older layers lay under the town. In 1991 the team found a human lower jaw, catalogued D211, in the old layers, at a time when Georgia was in political turmoil after the break-up of the Soviet Union. The dig, led by David Lordkipanidze after the 1990s, has continued ever since, with the Georgian National Museum and international partners.
The fossils
Between 1999 and 2005 the team found a set of skulls and bones from several individuals, and a fifth skull, catalogued D4500, published in 2013:
- Five skulls. Of adults and adolescents, with brain sizes from about 546 to 775 cubic centimetres, much smaller than the later Homo erectus of Asia, but with faces and limbs more like early Homo.
- D4500 and the jaw D2600. A skull with a large face and a long, heavy jaw that fits it, the jaw found in 2000 and the skull in 2005. Together they are the most complete adult early Homo skull with a lower jaw.
- D3444. An older individual who had lost almost all of his teeth, well before he died. He must have survived for some time on soft food, and probably with help from others.
- Limbs. Bones of the body, which suggest people about 1.45 to 1.6 metres tall, with arms and legs mostly like those of later Homo erectus, but with some primitive features of the shoulder.
The tools are simple Oldowan flakes and choppers. Cut marks show they butchered animals. Meat from large animals such as deer, along with the remains of sabre-toothed cats, giant cheetahs and wolves, show that people lived in the same landscape as dangerous predators.
What it changed
The Dmanisi people were smaller-brained than expected, which showed that people left Africa before they had large brains or advanced tools such as handaxes. The five skulls are also very different from each other, in shape and size, but they all came from one place and time. Lordkipanidze and colleagues argued in 2013 that this variety is that of one population, and that early fossils given different names, such as Homo habilis, rudolfensis and erectus in Africa, might really belong to one lineage, variable like Dmanisi’s. Not all researchers accept that, but the idea has shaped the whole debate on how to name early Homo. Some call the Dmanisi people Homo erectus georgicus, and others use Homo georgicus.
Visiting
The Dmanisi Museum-Reserve is open to visitors, with a path to the excavations and the medieval ruins, and displays in the Georgian National Museum in Tbilisi. See also Homo erectus.
Sources
- Lordkipanidze, D. and others (2013). A complete skull from Dmanisi, Georgia, and the evolutionary biology of early Homo. Science 342: 326 to 331.
- Gabunia, L. and others (2000). Earliest Pleistocene hominid cranial remains from Dmanisi, Republic of Georgia. Science 288: 1019 to 1025.
- Lordkipanidze, D. and others (2005). The earliest toothless hominin skull. Nature 434: 717 to 718.
- Ferring, R. and others (2011). Earliest human occupations at Dmanisi (Georgian Caucasus) dated to 1.85 to 1.78 Ma. Proceedings of the National Academy of Sciences 108: 10432 to 10436.