Scientists have found a fossil of a pregnant marine reptile that lived millions of years before the dinosaurs, reported Reuters. The discovery of the animal with its developing embryo sheds lights on the evolution of vertebrate reproductive systems, because it implies that the reptile did not lay eggs but gave birth.

The fish-eating reptile is called Dinocephalosaurus, and it lived during the Triassic Period, around 245 million years ago. Dinocephalosaurus is the first member of the vertebrate group called archosauromorphs. The group includes birds, crocodilians, dinosaurs and extinct flying reptiles known as pterosaurs. The animal found is 13 feet long with a slender, 5.5-foot-long neck, paddle-like flippers, a small head and large canines.

The fossil was found in Yunnan province, China. Palaeontologist Jun Liu of China’s Hefei University of Technology said the flying snakes were also viviparous, which means they gave birth to live babies instead of laying eggs. “I think you’d be amazed to see it, with its tiny head and long snaky neck,” said University of Bristol palaeontologist Mike Benton. The scientists have published a paper on the discover and subsequent research in the journal Nature Communications.

However, there has been speculation that animal’s abdomen could also have contained its prey and not its baby. Several such fossilised animals have been found in the past with their prey intact in their stomachs. However, Liu pointed out that it was found in a curled posture, which is typical of vertebrate embryos. Moreover, the embryo faces forward whereas predators generally swallowed animals head first.