Dmanisi, Kvemo Kartli, Georgia
Dmanisi skulls
1.85 to 1.77 million years (five skulls, one of them 546 cubic centimetres, with simple flake tools)
Under a medieval town in southern Georgia, five early human skulls have come out of layers dated between about 1.85 and 1.77 million years ago. One of them, Skull 5, has a braincase of 546 cubic centimetres and a large, projecting face. The tools with them are simple flakes, not handaxes.
Why this is extraordinary
A medieval town in southern Georgia sits on an early human deposit. The fossil site was recognised in 1983. Through the 1990s and after, five skulls came out of the layers under the walls, with jaws and a large collection of limb bones, and with stone tools that are flakes and cores. Not handaxes. The hill is about 910 metres up, where a lava flow once dammed a river and made a lake. Less than a tenth of the bone bed has been dug. The layers are up to about 4 metres thick.
The dates are the volcanic ash and the earth’s magnetic field. Repeated visits fall in the late Olduvai interval, about 1.85 to 1.78 million years ago. The skulls themselves sit near 1.77 million, and the younger limit of the package is about 1.76. That is earlier than the old textbook exit from Africa, the one that waited for a bigger brain and a handaxe and for Homo erectus to be obvious in East Africa. A 2011 reading of the dates goes further and says the Caucasus was occupied before that East African erectus appears. The comparison is only as good as the African list. Rename one skull, or date one earlier, and the sentence moves.
Skull 5 is the complete one, cranium D4500 and jaw D2600. The braincase measures 546 cubic centimetres. The face is large and projects, and the teeth are large. The other four vaults are bigger, with published figures from about 600 cubic centimetres into the 700s. The bodies reach the short end of modern stature and are built for walking. So a small brain was enough to be in Georgia. The 2013 paper treats all five as one population, wide in its faces, and takes that width as the reason to stop splitting early Homo into several species. The other reading keeps the splits. Skull 5’s face looks earlier, the braincase looks more like erectus, and the lakeshore was in use for as much as about 80,000 years, which is time enough for more than one group. One of the five, D3444, is an old adult who had lost the teeth and went on living. That is difficult without soft food from someone else. It does not choose the species name.
No star or solstice reading belongs to a fossil lake shore, and none is added. What this changes: the first people outside Africa, on these dates, are early, small-brained, and carrying a simple toolkit. The name on the skulls can still be argued. The timetable is the part that moved.
Why it matters
An older textbook had the first people leave Africa later, with a bigger brain and a handaxe, once Homo erectus was already established in East Africa. Dmanisi is earlier than that story, smaller-brained, and already in the Caucasus. If these five skulls are one species, a lot of fossils that wear different names may be the variation inside a single lineage. If they are more than one species, the Caucasus had a crowd at the beginning.
Dmanisi is a hill town in Kvemo Kartli, about 910 metres up. A medieval fortress sits on the deposit. The paleontological site was recognised in 1983, and the hominin skulls came out of the layers beneath the town from the 1990s onward. There are five crania, with jaws and a large set of limb bones, the richest early Homo collection from any one place this old. The tools are Oldowan, cores and flakes. The Acheulean handaxe is not the kit. A 2011 study of the geology puts repeated occupation through the late Olduvai magnetic interval, about 1.85 to 1.78 million years ago, and puts the hominin fossils themselves at about 1.77 million, with a younger limit near 1.76. The same paper’s reading is that the southern Caucasus was occupied before the fossils usually called Homo erectus appear in the East African record. That reading depends on which African skull you are willing to call erectus. It is part of the argument, not a settled border.
Photo tour
3 photographs, unedited. On a phone, swipe the row. Choose one to look closely.
What is still unexplained
These sit beside the consensus account, with the same visual weight. None of them is marked solved.
Location and dating
- Location
- Under the medieval town of Dmanisi, near Patara Dmanisi, Kvemo Kartli, Georgia. The coordinate is the paleontological site. Less than a tenth of the deposit has been excavated. The bone-bearing layers are up to about 4 metres thick, on basalt, where a lava flow once dammed a river into a lake.
- Period label
- Current consensus — open to revision Early Pleistocene, about 1.85 to 1.76 million years ago for the occupations and the fossils. Outside Africa, this is the earliest well-dated hominin site with skulls.
- How this dating was done
- Argon dating on the volcanic layers, the flip of the earth’s magnetic field at the end of the Olduvai interval, and the animals in the same sediments. The tools are typed as Oldowan by their shape. There is no radiocarbon clock at this age. Radiocarbon does not reach it.
- What could change it
- An African erectus skull, securely older than 1.85 million years, would put the Caucasus back behind East Africa. A sixth skull at Dmanisi that cannot be fitted into the same range of faces would revive the several-species reading on the spot.
What is actually there
- Five crania come from one site, with Oldowan flakes and cores, not handaxes.
- Skull 5 combines a 546 cubic centimetre braincase with a large projecting face.
- The other four braincases are larger, from about 600 cubic centimetres into the 700s.
- Occupation runs for as much as about 80,000 years.
- One old adult, D3444, had lost the teeth and lived on.
- The medieval town stands on the deposit. The site was recognised in 1983.
Open questions
| Question | Status |
|---|---|
| Did people reach Eurasia before Homo erectus is recognised in East Africa? | Open. The Dmanisi ages are early. The African comparison depends on which skull counts as erectus. |
| Are the five skulls one species? | Open. The 2013 paper says yes, a wide lineage. A face like earlier Homo and a braincase like erectus lets the split stand. |
The current narrative
Where publication stands today. It is the best-supported reading, and it is open to revision. It is not a verdict.
The current narrative — open to revision
One variable lineage, out of Africa early
Dmanisi is early Homo, a single population with a wide range of faces and brains, in the Caucasus by about 1.85 to 1.77 million years ago, carrying Oldowan tools and a brain that had not yet reached later erectus size. The first exit did not require a handaxe or a large brain.
What supports this
- Five crania from one site and one broad window show more variation than a single “type” skull would allow, which is the 2013 argument for one lineage.
- The argon and magnetic dates put occupation at 1.85 to 1.78 million years, fossils near 1.77.
- The tools are flakes and cores. A big brain and a handaxe are not in the deposit.
What pushes back
- About 80,000 years is long enough for more than one population to use the same lake shore. Same site is not the same family.
- Skull 5’s large face and 546 cubic centimetre vault can be read as an earlier kind of Homo sitting near a more erectus-like braincase, which is how several species survive the same quarry.
- “Before African erectus” depends on the African list. Move one African skull earlier, or rename it, and the slogan changes.
What would settle it
Best-supported for the age, the small brain, and the simple tools. The single lineage is the reading the five skulls were published to defend, and a long occupation keeps a crack in it.
Emerging narratives
Other published readings. Each may be right. None is adopted here unless the evidence carries it.
An emerging narrative
More than one kind of human at the same lake
The Dmanisi sample mixes early Homo of more than one species. Skull 5 stays close to the earlier African faces. Other vaults sit nearer erectus. The names habilis, rudolfensis, erectus, or a local georgicus, still sort real differences, and one hillside does not erase them.
What supports this
- Skull 5 pairs the smallest braincase with the largest face, a combination the 2013 paper itself calls previously unknown. A combination can be a join of two kinds.
- The occupation spans as much as about 80,000 years. Time is room for replacement as well as for neighbours.
- A local name, Homo georgicus, was used for these fossils before the single-lineage reading, and the file labels on museum casts still hesitate.
What pushes back
- The 2013 study measured the five crania against one another and against early African Homo and argued the spread fits one paleodeme.
- Splitting them again needs a line through the sample that is not just the biggest face against the smallest brain. Size differences inside one species are ordinary.
- The exit from Africa, the date, and the Oldowan tools do not change if the name on the label changes.
What would settle it
A live taxonomic argument. It does not restore the old timetable in which nobody leaves Africa until the brain is large and the handaxe is in the bag.
Should the current view be reevaluated?
Open to revision
The date, the five skulls, the 546 cubic centimetre braincase, and the flake tools are enough to retire a late, large-brained, handaxe exit. Whether those skulls are one species is still a real argument about a definition and about 80,000 years of layers. Open keeps the timetable and the name apart.
What drives this
- Occupations about 1.85 to 1.77 million years ago, outside Africa.
- Skull 5 at 546 cubic centimetres, with a large face, among five crania.
- Oldowan tools, and a species name that the same bones can still move.
This is the museum’s own weighing of the evidence. It is not a visitor vote, and it is separate from the slider.
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If the contested reading is right
What would follow if a reading that is not the consensus turned out to be true, and what could settle it. This explains the stakes. It does not adopt the reading.
One small-brained lineage left Africa before the handaxe
The first Eurasians would be taught as early Homo with a modest brain and a simple toolkit, and several African species names would be folded into that lineage’s variation. Later erectus would be a change inside the group, not the traveller who opened the gate.
Why it is still worth a test
More skulls of this age from the Caucasus and from East Africa, dated on the same argon and magnetic clocks, measured for the face and the vault together.
Sources
- A complete skull from Dmanisi, Georgia, and the evolutionary biology of early Homo Science, 2013
- Earliest human occupations at Dmanisi dated to 1.85–1.78 Ma PNAS, 2011
- Dmanisi hominins Wikipedia, for the specimen list and the published braincase figures
Image credits
- A Dmanisi skull from the front, photographed at the Georgian National Museum. The brow is heavy and the vault is small. The file dates it to 1.8 million years and does not name which of the five crania it is. . Jonathan Cardy, CC BY-SA 3.0. Shown unedited.
- D3444, the old adult, at the Smithsonian. The jaws are worn down and the teeth are gone. The file’s own title leaves the name open, Homo erectus or Homo georgicus. . Ryan Somma, CC BY-SA 2.0. Shown unedited.
- The file identifies this fossil in the Dmanisi deposit as Skull 5, D4500. The bone is the colour of the sediment around it, and the outline is soft. It is the layer, not the cleaned museum skull. . Guy Bar-Oz, CC BY-SA 3.0. Shown unedited.