NORTHERN CHINA ERODED BASIN UNCOVERS WHAT COULD BE A PLAYGROUND OF EARLY HOMINIDS NEARLY TWO MILLION YEARS AGO
Examination of stone artifacts between 1.77 and 1.95 million years old suggested that they could be toys played with by children. “This is an amazing discovery,” said professor Wei Qi, paleoanthropologist with the Chinese Academy of Sciences and lead scientist of the project at the Heitugou site in Nihewan basin, Yangyuan county. “The site is a treasure chamber that may hold some useful clues to answer a lot of important questions, from the social structure of the early hominids to whether, when and how they arrived in Asia all the way from Africa.”
The “playground” was not big, but seemingly bustling with activity. In an area less than six square meters, scientists found more than 700 stone artifacts with nearly 20,000 fragmented pieces. Wei, now retired and spending most of his time at the site, believed that these stone pieces were made by the hands of children and women. More than 80 per cent of them were small, ranging 20 – 50mm in length, with most carrying no sign of wear by use at all.
There is other evidence suggesting the site was a playground instead of a living or working area. Researchers failed to find large amount of animal remains that are common in a habitat, and the near absence of large size stone tools could be a sign that few adult workers were involved in these activities. Though the site was discovered as early as 2002, it was not until recently that the scientists were able to date it with any certainty.
Using a geochronological tool called magnetostratigraphy, which analyzed the direction change of the ancient Earth’s magnetic field that was recorded in the site’s sediment, the scientists found the Heitugou site to be older than the famous Dmanisi site in Georgia, which was regarded the earliest known hominid site outside of Africa.
The concentrated distribution and little wear showed that they were buried by a sudden event, likely a landslide, which protected them from later exposure to winds and precipitation. Before the catastrophic event, the playground was likely a small paradise. Nihewan basin, now a rugged landscape with deep gorges, used to be an enormous lake which provided an ideal habitat for early hominids. In the past century, researchers have discovered numerous early hominid sites in the area.
But Wei’s discovery at the Heitugou site was not without controversy. Gao Xing, researcher with the CAS Institute of Vertebrate Paleontology and Paleoanthropology, said the biggest concern was whether the stone pieces were all made by hand.