First 3D Ancient Pterosaur Eggs Discovered with the Fossils of Their Flying Parents

Paleontologists have made a startling discovery. They've found the first three-dimensionally preserved pterosaur eggs in China. Not only that, but the eggs were found among dozens, if not hundreds, of pterosaur fossils. The findings could reveal a bit more about the life cycle of these ancient flying reptiles, giving researchers a glimpse into the ancient past.

The site where the eggs were found is located in the Turpan-Hami Basin, south of the Tian Shan Mountains in Xinjiang, northwestern China. Researchers believe that the fossil-rich area may harbor thousands of bones, and that the pterosaurs found there probably died during a large storm.

The eggs were laid by a new genus and species, Hamipterus tianshanensis. It's likely that these pterosaurs lived in gregarious colonies, like some birds today, about 120 million years ago. In all, the scientists discovered five eggs that were preserved three-dimensionally.

What's most exciting, though, is the fact that these creatures have been preserved at all. The fossil record of the pterosaurs has generally been poor, with little information about their populations. In fact, prior to this find only four isolated and flattened pterosaur eggs have been found.

So what were these eggs like during their lifetime? The eggs were pliable, with a thin, calcareous eggshell outside and a soft, thick membrane inside-similar to the eggs of some modern-day snakes. Because of the large number of pterosaurs and eggs, it's very likely that there was a nesting site nearby. Hamipterus likely buried their eggs in sand along the shore of an ancient lake to prevent them from drying out.

"Sites like the one reported here provide further evidence regarding the behavior and biology of this amazing group of flying reptiles that has no parallel in modern time," wrote the researchers in a news release.

The findings are published in the journal Current Biology.