A rare fossil has been discovered in China’s Anhui province, which shows a female Chaohusaurus reptile giving birth to its offspring head first.
The findings are published in the journal PLOS One and describe the preserved partial skeleton of the mother with its tail extending to the right, ribs on the left, and pelvis and hind flipper in the centre. The preserved skulls of one embryo can be seen inside the mother, with another exiting through her pelvis, and a third baby beneath her tail showing that she likely died giving birth on land and was fossilised in that position.
This fossil, form around 248 million years ago during the early Triassic period, shows how reptiles evolved to give birth on land according to scientists, contradicting the traditional interpretation that viviparity, producing living young without eggs, was an aquatic adaptation.
The fossils were discovered by a team of researchers from the US and Peking University and Anhui Geological Museum in China, when they were looking for fossils of different species of predatory fish called Saurichthys. When investigating the slab of rock they noticed the fossil of a Chaohusaurus with her babies.