Palaeoanthropologists later pieced it together with more fragments found at the site to form much of the skull of a early human that lived in southern China more than 130,000 years ago.

The Maba specimen was neither the oldest nor the best preserved early human remains found in China, but something set it apart: it had a “European” face with distinct featuresthat resembled those of a Neanderthal, a human species that roamed Europe before modern humans arrived from Africa.

That raised the question of whether the Maba skull was from a species of human that originated in Europe, a kind of prehistoric Neanderthalian Marco Polo.

The biggest problem to finding an answer was the incompleteness of the fossil. Its lower face was missing and there were numerous gaps in the brain casing.

So a joint Spanish and Chinese research team scanned the specimen and filled in the gaps with digital technology, leading to some surprising results.

Professor Emiliano Bruner, co-author of the study at the National Research Centre for Human Evolution in Spain, said the Maba specimen’s face had some strong structural parallels with Neanderthals.

“The similarity is really striking,” Bruner said.

But the biggest surprise was the shape of the brain casing, which seemed from a much earlier time.

It was a strange combination – a Neanderthalian face and an archaic brain – but a similar mix had been found in another hominid, Homo heidelbergensis. That species lived in Europe as long as 300,000 years ago and was a candidate ancestor or early form of the Neanderthal, with remains mostly found at a site in Spain.

The combination raised two possibilities: Maba man was either an early Neanderthal, meaning the Neanderthal range must have included eastern Asia, or it shared the same ancestor as the Neanderthals.

“In both cases, there is room to think about an unknown Euro-Asian evolutionary process,” Bruner said.

But co-author Professor Wu Xiujie, from the Chinese Academy of Sciences’ Institute of Vertebrate Palaeontology and Paleoanthropology in Beijing, suggested there could be a third possibility.

“There is a chance that he is from a native species that developed the same features independently in parallel evolution,” she said.

Wu admitted the chance of parallel convergence was low, and it was more likely that the Maba specimen belonged to an early “Marco Polo” from Europe.

“But unlike Marco Polo, who completed his journey in a lifetime, the Maba arrived in south China after many generations of constant migration east, each generation passing their genes and distinct physical traits to the next,” she said.

Their paper was published in the American Journal of Physical Anthropology in March.

Another researcher at the institute, Professor Liu Wu, who was not involved in the study, said the wealth of discoveries in China in the last decade suggested modern humans almost identical to today’s Chinese populated southern China more than 100,000 years ago, challenging the popular theory that new migrants from Africa wiped out all native human species in East Asia when they arrived about 60,000 years ago.

Liu said Maba man could be a witness to the first Asian-European “conflict”.

A previous joint study by Chinese and American scientists suggested that the Maba skull fragments had signs of a serious injury, and “he” survived the wound, with bone regrown over the wound.

“If the Maba man was indeed a migrant from the West, he might found himself surrounded by a large number of native people, and the first encounter might not have been very friendly,” Liu said.

Bruner said it was too early to speculate on a specific conflict, and further studies, especially more fossil specimens, would be needed to end the mystery of the Maba fossil.

DNA analysis might shed some light but fossils more than 100,000 years old often did not have enough biological material for analysis.

“And evolution is more than a genetic algorithm … we need more fossils,” Bruner said.