A Skull That Could Change History

Oct 18, 2013 By Deepa Gopal
Deepa Gopal's picture

Dmanisi, Republic of Georgia. This region in Central Asia was once along the ancient Silk route, the famous trading route between the East and the West. Dmanisi also has a history going much further back... as far back as 1.8 millions years.

Under the medieval ruins of an ancient town and fortress at Dmanisi, archeologists have struck gold. In 1983, fossilized remains of extinct animals were found beneath the walls of the medieval structure as were stone age tools. Since then, this archeological site has revealed some of the most well-preserved human skulls outside of Africa, dating back to 1.75 millions years.

An unusual skull found in 2005 is now raising eyebrows in archeological circles, thanks to a recent study. We take a look.

The Existing Theory

The discovery of prehistoric skulls and artifacts, combined with the study of mitochondrial DNA, has helped scientists piece together clues to human origin and spread. It is widely accepted that modern humans or Homo sapiens first originated in Africa's Rift Valley about 200,000 years ago and spread to other continents in waves of migration.

But before the so-called modern humans, there were other early Homo species that had developed primitive tool-making capabilities and lived 1.8 to 2 million years ago. Based on physical characteristics, scientists have grouped them into Homo habilis, believed to be the first stone-tool makers; the larger-brained Homo rudolfensis; the slender Homo ergaster and the Homo Erectus, who were precursors to modern humans.

If you are wondering where the Neanderthals are in all this... well, they came along 200,000 to 300,000 years ago. They were a species of short and stocky humans who lived in the caves of Europe during the Ice Age. The Neanderthals are believed to have existed at the same time as modern humans but were wiped out due to climate changes. 

The Skull 5 Mystery

Between 2000 and 2005, archeologists at Dmanisi found a well-preserved adult Homo skull - they called it Skull 5. It also dated to 1.8 to 2 millions years ago but it was very different. With its long face, massive jaw, large teeth and small brain, it could have been mistaken for a different species except it was found with four other Homo skulls at the same site.

This raises the question - were there really so many early Homo species as scientists claim, or were these just differences among one species just as any five humans are different? Christoph Zollikofer, a co-author of the study points out that he is not lumping Neanderthals into this group - just the different Homo species that have been identified between 2 million and 1.8 million years ago.

There are some who disagree saying that such a claim cannot be made based on one skull finding. But there is no doubt that Skull 5 is indeed a mystery!