Here is primitive man, now all we have to do is find him!Swedish geologist Johan Gunnar Andersson first started his explorations of the region in 1918 at an area called Chicken-bone Hill by locals who had misidentified the rodent fossils that were found in abundance there,[7] but it was not until 1921 that he and American palaeontologist Walter W. Granger were led to the site known as Dragon Bone Hill by local quarry men.

Noticing some white quartz that was foreign to the area, he immediately realised that this would be a good place to search for the remains of primitive man.

[8] Excavations were undertaken by Andersson's assistant, Austrian palaeontologist Otto Zdansky in 1921 and 1923, unearthing a great deal of material that was sent back to Uppsala University in Sweden for further analysis.

In 1926, Anderson announced the discovery of two human molars amongst this material, and the following year Zdansky published his finding, cautiously identifying the teeth as ?Homo sp.

[citation needed]Canadian paleoanthropologist Davidson Black, who was working for the Peking Union Medical College at the time, was excited by Andersson and Zdansky's find, and applied to the Rockefeller Foundation for funding to undertake a systematic excavation of the site.

That fall, a tooth was unearthed by Swedish paleontologist Anders Birger Bohlin, which Black proposed belonged to a new species dubbed Sinanthropus pekinensis.

Black stayed on at the Laboratory as honorary director, while excavations continued at the site under Chinese paleontologist Yang Zhongjian, anthropologists Pei Wenzhong, and Jia Lanpo.

[17] Altogether, excavations uncovered 200 human fossils from more than 40 individuals, including 5 nearly complete skullcaps,[18] before they were brought to a halt in 1937 by the Japanese invasion of China.

Reports of Japanese atrocities include the torture and murder of workers at the site, with three bayoneted to death, and a fourth forced to pull a rickshaw until dying of starvation.

The site was originally a natural limestone cave, although the roof had long since collapsed, spreading a layer of breccia and rubble across the top of the deposits.

Excavations recommenced in 1949 and continued to yield fossils and artefacts, making this site one of the most fruitful sources of material from the Middle Pleistocene era.

Excavations have dug to a depth of 7m through Layers 3–6, and have unearthed stone tools, burned bones and ashes, and fossils of bird, reptile, and mammal species.

[34] Situated on the upper part of Dragon Bone Hill, this cave was discovered in 1930, and excavated from 1933–34, during which time the roof and north-facing opening were removed.

The cave was divided into an upper-level living quarters, and a lower-level burial ground, while a small recess on the lower level acted as a natural animal trap.

[42] Discovered in 1933, when Locality 3 was being excavated, this column-shaped corrosion pit is filled with red grit, and dates to the late Early Pleistocene era.