After graduating, Dong Zhiming began working at the
Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in
Beijing where he was mentored by
Yang Zhongjian, the "father of Chinese vertebrate palaeontology". Yang had helped initiate the formal study of fossils in China during the 1920s and continued to lead the field of Chinese palaeontology even after cooperation with foreign institutions ended in 1949. More than a decade later, he no longer participated in field work but was willing to take on Dong as a student, particularly after Dong made it clear he was interested in researching more challenging subjects like dinosaurs as opposed to invertebrates, for which fossils were more abundant and easily transported. On this expedition, Dong discovered fossils of a sauropod dinosaur.
Dashanpu bone beds Dong Zhiming's palaeontology research halted in 1965 when he became one of many academics ordered to participate in the
Down to the Countryside Movement, which saw him and 17 million other privileged youth in China sent to work on farms across the country. Dong worked on a farm in
Henan for one year and returned to Beijing just as the
Cultural Revolution was beginning. With the IVPP all but shut down, he was reassigned to work on geological surveys in southwestern China where he helped design irrigation systems. Nonetheless, his mentor Yang continued to study palaeontology and met with Dong often, encouraging him to continue his research in addition to his work for the state. Yang also returned to field work during this time, including a 1975 expedition in which he investigated reports of fossils being found by road crews in the town of Dashanpu,
Sichuan. Around this time, Dong petitioned the government to reinstate the IVPP's journal -
Vertebrata PalAsiatica - and returned to work at the IVPP. One of Dong's first missions after returning to palaeontology was to follow up on Yang's finds at Dashanpu, and in 1976 he discovered the first dinosaur fossils dating to the
Middle Jurassic that had ever been found in China. Although this represented a monumental discovery, it would be the last he shared with his mentor: Yang Zhongjian died on 15 January 1979. As international tensions eased, Dong Zhiming began to cooperate with international researchers in addition to Chinese scientists. After the discovery of fossils at Dashanpu by both him and Yang, Dong returned to the township in 1980 accompanied by a team of scientists from the
British Museum. Being familiar with the area, Dong elected to begin their search for fossils at a construction site for a planned
natural gas facility which had excavated the top of a nearby hill, and after entering the site he and his colleagues discovered an unexpected treasure trove of fossils. Dong and his team worked to end the construction on the hill, and by autumn the local government agreed to end development at Dashanpu despite having already invested over one million
yuan into the project. Historically, all dinosaurs have been categorized as belonging to either the order
Ornithischia or
Saurischia, and Dong's suggestion of a third order sparked controversy. American palaeontologist
Gregory S. Paul offered his support for Dong's theory in 1984, but that
Segnosaurus represented evidence not of a third order of dinosaurs but instead that all dinosaurs belonged to a single order. Ultimately, further research into both
Segnosaurus and
Therizinosaurus proved that the latter was a theropod and that the two belonged to the same order, and so the dinosaurs once proposed as belonging to Segnosaurischia were assigned to the order Saurischia. However, Dong continued to push this third-order theory as late as 2008, shortly before his retirement. During his field work, Dong also occasionally encountered modern farmers who believed that large dinosaur fossils were the remains of dragons, and had to convince them otherwise in order to acquire the fossils for study. This 1992 review saw Dong and Sereno determine that
Huayangosaurus had a parasacral spine, or a
vertebral column which ran adjacent to the
sacrum; and that the animal's heightened
pedicles may have helped keep its dorsal plates in place without
ossified tendons to hold them upright. ==Contributions and recognition==