The researchers determined that their eggs consisted of a thin, calcium carbonate shell covering a soft, thick membrane that surrounded the developing pterosaur.
"This makes pterosaur eggs similar to that of the 'soft' eggs of some modern snakes," Wang said, explaining that the eggs therefore had to be laid "in a moist environment, because the eggs needed water from the outside."
The snake similarity makes sense, given that pterosaurs were reptiles and would have been distantly related. Although pterosaurs had wings and could fly, they did not give rise to birds. All pterosaurs went extinct at the end of the Cretaceous, when non-avian dinosaurs and many other animals also died out.
It's even possible that pterosaurs and the earliest birds were archenemies.
Scientists at the University of Chicago and the Field Museum recently found that there was a striking lack of diversity among the earliest known birds.
"There were no swans, no swallows, no herons, nothing like that," lead author Jonathan Mitchell said. "They were pretty much all between a sparrow and a crow."
One feasible explanation is that the literal early birds continuously had to compete with pterosaurs. Another is that birds were simply newer to the scene and hadn't had time yet to diversify. In the long run, however, birds won out, surviving the mass extinction that did in pterosaurs.
The eccentric and social flying reptiles may be long gone, but their lifestyle and looks still make quite an impression. They are, for example, the subject of a huge exhibition featured now through early 2015 at the American Museum of Natural History.
As American Museum of Natural History spokesperson Kendra Snyder told Discovery News, "Pterosaurs were winged reptiles that flew with their fingers, walked on their wings, and ranged from the size of a sparrow to that of an F-16 fighter jet."