A site in the Turpan-Hami Basin, south of the Tian Shan Mountains in Xinjiang China contains is believed to have once been a pterosaur nesting site. The site was first discovered in 2005 and has been carefully excavated since that time. To site contains dozens and possibly hundreds of fossils which represent a new genus and species of pterosaur, Hamipterus tianshanensis.

Sediments in the record suggest that the animals died in and were buried by a large storm approximately 120 million years ago.

Most recently researchers have discovered five well preserved, three-dimensional eggs. Previously only four flattened pterosaur eggs have been discovered. Generally, pterosaur fossils are rare and information about the animals limited. This find, however, provides a good snapshot of their lives.

Based on what they’ve found at the site, researchers believe that the pterosaurs were social animals who shared common nesting sites. Examination of the eggs shows that they are similar to those of modern snakes, with a thin shell surrounding a soft but thick membrane. The eggs were probably laid in sand on a lakeshore to keep them moist until they were ready to hatch.

“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,” according to a statement from researchers at the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology.

For those interested in flying reptiles, a new exhibit at the American History of Natural History in New York features one of the largest collections of fossils ever assembled. The website for Pterosaurs: Flight in the Age of Dinosaurs features instructional videos and educational materials.

The latest findings from the dig in China can be found in the June 5 edition of the journal Current Biology.