Paleontologists from Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, and Swedish colleagues from Uppsala University, recently identified a unique canine tooth from Peking Man among the contents of the 40 cartons left unopened and forgotten at the Museum of Evolution at Swedish Uppsala University.

"The tooth has not been touched since it was dug up in the 1920s in China. We and our Chinese colleagues are overwhelmed. With today's technology, a canine tooth that has not been handled can tell us so much more than in the past, such as what they ate," said Per Ahlberg, professor of evolutionary developmental biology at Uppsala University.

Fossils from well-known Peking man are extremely rare, as most of the finds disappeared during World War II. All that remains in China today are five teeth and a few pieces of skull bone that were found in the 1950s and 1960s.

Swedish paleontologists were the first group of scientists to go to China in the early 20th century to carry out a series of expeditions in collaboration with Chinese colleagues. They found large numbers of fossils of dinosaurs and other vertebrates. The material was sent to Sweden and the well-known paleontologist Carl Wiman identified and described the fossils. But when the policy of research changed after Wiman's death, 40 cartons were left unopened and forgotten. Just a few weeks ago, Ahlberg and his colleague Martin Kundrat, and Museum Director Jan Ove Ebbestad noticed the cartons in a museum storeroom. They have gone through the material and contacted Drs. LIU Wu and TONG Haowen, from the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, who were excited and flew to Sweden to confirm the identification of the tooth.

"This is an extremely important find. It is the only canine tooth in existence. It can yield important information about how Homo erectus lived in China," said LIU Wu.

The Museum of Evolution kept the best collection of Chinese fossils of dinosaurs and other vertebrates outside of China, and the contents of the 40 cartons further enhance the value of the collection. The fossil material comes from several different areas in China. For example, specimens from Zhoukoudian, southwest of Beijing, were made of skulls and other skeletal parts, including this canine tooth from Homo erectus or Peking man.