Abstract:

Pterosaur researchers speculated that pterosaurs were oviparous for a long time, and they confirmed it based on the three pterosaur eggs and embryos from the Early Cretaceous reported in 2004. Then, a wukongopterid pterosaur associated with two similar-sized eggs, one outside body near the pelvis and the other inside, was discovered in the Yanliao Biota from the Late Jurassic. It indicated that the pterosaur had two functional oviducts, which differed from mostly modern birds. Five three-dimensionallypreserved pterosaur eggs were first reported from the Early Cretaceous in Hami, Xinjiang, China. The eggshell of one egg, observed under scanning electron microscopy, comprises a thin calcareous external hard shell followed by a thick membrane, which is similar to that of the snake Elaphe. It is hopeful to discover some three-dimensional pterosaur eggs with embryos in Hami, which will make a great progress in pterosaur embryology in the future.