Washington, Feb 21 : Archaeologists have discovered an ancient human skull in China, dating back to 80,000 to 100,000 years, which may shed light on a shadowy chapter of evolutionary history.
The finding was made by an excavation team led by Chinese archaeologist Li Zhanyang in the central province of Henan.
According to National Geographic News, a report from the Chinese government earlier suggested that the fossil came from a modern human, which would have forced a radical reworking of current theories about when our species first left Africa.
But, experts have said that the skull likely belongs to a sister or precursor species to modern humans.
While still too early to judge the skull's true significance, it hails from a pivotal evolutionary period, when modern-day humans began to supplant the ancestral human species Homo erectus.
According to experts, the discovery raises the chances that the two species may have overlapped for some time in China, possibly interbreeding and sharing tools.
"The skull shows characteristics of both archaic humans and of Homo sapiens," said Li.
"If this is a 'modern' Homo sapiens, with a high rounded skull, divided browridge, and chin, and is 80,000 to 100,000 years old, then it would indicate a very early dispersal of moderns eastwards from Africa and the Middle East," said Chris Stringer, a research leader in the Human Origins Program at the Natural History Museum in London.
But according to Stringer, the fossil is much more likely to be that of an earlier species.
Erik Trinkaus, a paleoanthropologist at Washington University in St. Louis, Missouri, offered a similar assessment after viewing photos of the Henan skull.
"Based on the anatomy of the skull, with its large projecting browridge, this appears to be close to Peking Man," he said.
The "Peking Man" refers to a series of half-million-year-old skulls belonging to Homo erectus, which were found in a massive cave on the outskirts of Beijing in the 1920s and 1930s.
Experts have said that the discovery of the older Henan skull is important because it increases the possibility that archaic and modern humans coexisted for a time in China, just as they did in Europe.
According to Trinkaus, these varying species might sometimes have interbred. The modern human fossil he studied in Beijing featured archaic traits that might have marked it as an inter-human hybrid.