An embryo (inset) preserved inside a fossilized Dinocephalosaurus found in Yunnan province, China.Credit: J. Liu et al. Nature Commun. 8, 14445 (2017).

Around 245 million years ago, just over 150 kilometres east of what is now the city of Kunming in southern China’s Yunnan province, a pregnant Dinocephalosaurus died. In February 2017, the long-necked, flesh-eating marine animal and her fossilized embryo provided proof that members of her animal group could give birth to live young. Previously, researchers thought that the Archosauromorpha, ancient reptiles whose modern-day ancestors include crocodiles and birds, only laid eggs.

Palaeontologist Liu Jun and his team at the Hefei University of Technology in China published their analysis of the fossilized beast last year (J. Liu et al. Nature Commun. 8, 14445; 2017). The specimen was one of 10,000 collected during 2008 in Luoping Biota National Geopark, an area that was long ago covered in shallow water. This is what helped to preserve the fossil after it died, says Liu.

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Liu hopes that the finding will inspire other scientists to look for further evidence of live births in ancient reptiles, adding that studying fossils that have already been excavated could be as fruitful as searching for newly uncovered examples. He cites a 2011 Science paper showing live birth in a plesiosaur, a marine predator that went extinct around 66 million years ago. The plesiosaur specimen was excavated in 1987 in Kansas (F. R. O’Keefe & L. M. Chiappe Science 333, 870–873; 2011). “We need to do more work with older specimens,” Liu says.

Liu said that he received financial support from the China Geological Survey (CGS) and the National Natural Science Foundation of China. He suggests that although science funding levels in China are extremely healthy, they can be tied to the whims of leadership figures. China’s former Premier, Wen Jiabao, used to be a geologist. When Wen retired in 2013, “geological research and investment went down, with less and less funding from the CGS”, says Liu.