Pterosaur species
Pterosaur egg with fully developed pterosaur embryo, from the Jingangshan beds of the Yixian formation, Liaoning, China.
Specimen: JZMP-03-03-2
Analysis suggests that the egg contains a type of ornithocheirid pterosaur, showing some soft tissues. The egg appears to have been soft shelled.
Ji Q., Ji S.-A., Cheng Y-N., You H-L, La J-C., Liu Y-Q and Yuan C-X; 2004, Palaeontology: Pterosaur egg with a leathery shell. Nature 432, p.572 (2 Dec 2004)