One of the most dramatic discoveries in the study of human origins has been revealed by scientists: a perfectly preserved fossilised skull of an ape-like man who lived about 1.8 million years ago.
The discovery, along with the remains of four other individuals who lived at the same time and in the same place, has generated intense excitement among palaeontologists who believe the finds could rewrite the early history of human evolution.
The skull and its lower jawbone were found at a site near Dmanisi in the foothills of the Caucasus range in Georgia.
Researchers have spent eight years studying the skull, together with its jawbone, which was discovered in 2000 but has only now been reunited with its "owner".
The first scientific description of "skull 5", published in the journal 'Science', indicates that the adult male had a large, long face with heavy features including a large jaw. Yet he had an exceptionally small brain case – the part of the skull containing the brain – which is less than half the size of a typical human's today and not much bigger than a gorilla's.
Ian Tattersall, of the American Museum of Natural History in New York, told 'Science' that the skull is "undoubtedly one of the most important ever discovered"; Tim White of the University of California, Berkeley, has described it as "an iconic fossil".
The four other skulls are thought to have belonged to an elderly, toothless male, another adult male, a young female and an adolescent of unknown sex. Dating technology based on argon isotopes found that they lived between 1.77 million and 1.85 million years ago. "Dmanisi is a unique snapshot of time – maybe a time capsule that preserves things from 1.8 million years ago," said Professor David Lordkipanidze of the Georgia National Museum in Tblisi, lead author of the study. What has surprised the scientists is the range of physical variation. This has led them to suggest that several other early human species living at about the same period in Africa may in fact all belong to the same species.
The five skulls from Dmanisi "look quite different from one another, so it's tempting to publish them as different species", said Christoph Zollikofer, a neurobiologist at the Anthropological Institute and Museum in Zurich. "Yet we know that these individuals came from the same location and the same geological time, so they could, in principle, represent a single population of a single species."
The scientists suggest that the Dmanisi individuals probably belonged to Homo erectus, the first human species to emerge from Africa. They also think that other species only found in Africa, such as Homo habilis, may in fact be the same species as Dmanisi man. (© Independent News Service)