The site was first discovered by the Scottish geologist
George Barbour in 1923. He was amazed when he saw the ancient sediments from the lake. Although he guessed wrong about how old they were and found basically nothing, Barbour invited Pere Licent and Pierre Teilhard de Chardin, two of the most brilliant prehistoric archaeologists of that time, for a visit. Licent and Chardin not only pushed the sediment's age to over a million years but also found, among many things, a flint tool. It was the oldest stone tool found at the time - so old, in fact, that even Chardin himself had suspicions about its authenticity. Barbour invited French archaeologists
Pierre Teilhard de Chardin and
Émile Licent. In 1935 Teilhard found a stone (flint) tool and determined the age of the site to be over a million years – it was the oldest artefact then known. Many scientists, including Teilhard, debated whether this tool might not be naturally formed. The discovery by
Pei Wenzhong of
Peking Man hundreds of kilometers to the south (followed by wars and revolution) distracted the attention of the world's scientific community. However, from 1972 to 1978 more than 2000 pieces of stone tools were discovered, together with some bone tools, which confirmed Xiaochangliang (or
Nihewan) as a Paleolithic site. In the basin, Archaeologists have identified 40 "million year old sites". ==Notes==