Once again Black presented the artifacts to the Rockefeller Foundation hoping to receive more funding. This time he succeeded and walked away with $80,000. He also had enough money to create The Cenozoic Research Laboratory a special division of the Chinese Geological Survey, which investigated artifacts between 2 million and 65 million years old.
During the late 1920s, the civil war significantly escalated in China, especially in the Chou Kou Tien region. In the midst of the ongoing battle among bandits and warlords, scientists continued to dig at the site searching for more evidence.
For much of the world 1929, with the famous stock market crash, was a terrible year. But, for the Chou Kou Tien paleontologists, 1929 was a glorious year. Pei Wenzhong, the newly appointed general director of the site, was a very persistent man. He had reached a layer of black fossilized clay of uncertain magnitude that was almost impenetrable. After weeks of work, his workers finally broke through the layer and were rewarded with a large cache of animal bones. But it was late November and it was freezing. Pei found a crack in the surface that allowed him and a colleague to be lowered down into the chasm by ropes.
Penny van Osterzee describes the remarkable operation:
It was in the afternoon on 2 December 1929, near sunset with a winter wind bringing freezing temperatures to the site. There were four men down in the chasm, working in a space so narrow that each had to hold a candle in one hand and work with the other Whats that? Pei cried out as a feeble candle flame of one of his companions flickered over a curved shape. Pei scrambled over to the spot, holding his breath in excitement. A human skull!
Skull cap found at site
Pei found an uncrushed human skullcap half embedded in rock and sand. The men worked vigorously into the night to free the delicate skull. Once it was released Black examined it and confirmed that it was from the Pleistocene period. The discovery was an international news sensation catapulting Black and his colleagues to instant fame in the scientific community and world.
Excavation of area in cave
During the early 1930s, evidence of early man continued to be discovered, including stone tools and proof that they used fire. The material found prompted more research and endless debates over how the Peking Man lived and looked. Black was especially exuberant about each new find and he worked continuously examining the enormous quantity of artifacts. He was so determined to complete his study that his health became affected by the increasing strain and lack of sleep. On March 15, 1933, while conducting laboratory work on the fossils, Black died of a massive heart attack.
Dr. Franz Weidenreich
Even though Black was deeply missed, the scientists knew that they had to continue with the work he started. In 1935, the renowned anatomist and anthropologist Dr. Franz Weidenreich took on Blacks position as head of the Cenozoic Research Laboratory. Weidenreich had a difficult job before him because after Blacks death nothing of significance had been found and the money for excavation was dwindling. The pressure to produce results steadily increased.
Finally, after several years a new discovery was made. On October 22, 1936 workers uncovered a complete jaw. It was a significant find because they now had evidence of a second hominid. Surprisingly, the following month two more skulls were found in just one day. At that point it was clear that they stumbled on to a much bigger find than ever expected. From then on, the funds poured in.
As the excavation continued into 1937, a wealth of material was unearthed, which included teeth and bones representing approximately 40 people. According to Shapiro, it was the largest collection ever made of a single fossil population of hominids Moreover, the remains of both men and women were the oldest that had ever been found.
Reconstructed Sinanthropus pekinensis
Scientists now had a clearer picture of how the ancient population may have looked. They were believed to have been small in stature ranging between 4 feet, 8 inches and 5 feet, 1 inch tall. They also had jutting brows, collapsed chins and broad noses. It was also believed that they walked upright and were likely to have weighed approximately 100 pounds. Weidenreich believed that the physical characteristics of Peking Man somewhat resembled that of modern Chinese.
Just as scientists were beginning to understand more about the Peking Man, excavation at Chou Kou Tien abruptly stopped in July 1937. Japan invaded China, resulting in a full-fledged war and putting at risk all those working at the site. Even though the excavation was halted, researchers continued to work on the specimens they had amassed at the research lab. However, it was only a matter of time before work at the PMUC also would be brusquely interrupted.