London, Sept 20 : Palaeontologists have discovered a treasure trove of the oldest human skeletons outside Africa, a find they say may fill crucial gaps in the story of our evolution, and help improve our understanding of the biology of the 1.8 million year old hominins.

The work, led by researchers from the Georgian National Museum in Tbilisi, describes three-dozen fossils from the skeletons of four primitive Homo erectus individuals found in recent years at Dmanisi in Georgia, central Asia.

H. erectus is thought to have migrated across Asia after coming out of Africa, where the oldest relative of man is traced to nearly 7 million years ago. H. erectus fossils have been found from Africa across Asia as far as Indonesia.

Typically there are only a few scattered fossils at one location. A single site with so many bones from so many individuals is rare.

The scientists say these fossils date back to very soon after H. erectus's exodus from Africa.

“Dmanisi is a real gift, because nothing in the world exists like this for this time,” said lead author David Lordkipanidze.

“The really important point is you have multiple individuals from the same time and location,” added Tim White, a palaeoanthropologist at the University of California, Berkeley, who was not involved in the work.

Lordkipanidze said, though the hominins “hands were well adapted to life in the trees,” the species also had modern human features, including long legs and a spine suited for long-distance running and walking.

The human ancestor had more humanlike body proportions than pre-Homo species, but likely slept in trees at night for safety, Lordkipanidze said.

The researchers said, together the specimens – three adults and an adolescent –presented a much better picture of what the species was like as a whole than would a single skeleton.

With one individual, it is difficult to determine whether a feature such as leg length is typical of the entire species or just characteristic of that one individual. But with four skeletons, it is reasonably easy to compare with modern humans, said Alan Walker, a palaeoanthropologist at Pennsylvania State University in University Park.

The scientists are now attempting to link these fossils to three skulls, a cranium and a mandible all found previously in the same dig site.

The findings appear in the journal Nature. (With inputs from ANI)