First known Neanderthal family clan fossils discovered in Siberian caves

The remains were found in two sites -- Chagyrskaya and Okladnikov caves -- in the Altai Mountains of southern Siberia, according to research published in the journal Nature.

The researchers said Neanderthal occupation deposits at Chagyrskaya Cave accumulated between 59,000 and 51,000 years ago. Analysis done on the fossils indicated these were close relatives living in a group of about 20 people.

This discovery is providing new insights into Neanderthal social organization.

"Because we find high amounts of homozygosity in all individuals, we conclude that the local community size of the Chagyrskaya Neanderthals was small," researchers wrote. "The best-fitting scenarios assumed a community size of 20 individuals, with 60-100% of the females being migrants from another community."

Swedish geneticist Svante Paabo was part of the research team.

"I would not have thought we would be able to detect a father and daughter from bone fragments, or Neanderthal DNA in cave sediments, or any other of the things that are now becoming almost routine," said Dr. Pääbo. "It has been an amazing journey."

The Russian Neanderthals were from a small band estimated to be 10-20 people and may have died together, likely of starvation, in the caves, according to the research. Evidence gathered shows a genetic link to Neanderthal populations thousands of miles away in Europe.

"Although the communities from Chagyrskaya and Okladnikov caves were genetically distinct, they all appear equally related to European Neanderthals and were part of the same Neanderthal population," researchers wrote. "No individual showed evidence of recent gene flow from other Neanderthal populations."

Richard G. Roberts, an Australian scholar and co-author of the study, said this Neanderthal clan most likely died very closely in time.

"They're so closely related, it's like a clan really living in this cave," he said. "The thought that they could go on for generations upon generations seems unlikely. I think probably they all died very closely in time. Maybe it was just a horrendous storm. They are in Siberia, after all."