Wing membranes preserved in pterosaur embryos are well developed, suggesting that pterosaurs were ready to fly soon after birth. However, tomography scans of fossilised "Hamipterus" eggs suggests that the young pterosaurs had well-developed thigh bones for walking, but weak chests for flight. It is unknown if this holds true for other pterosaurs. Fossils of pterosaurs only a few days to a week old (called "flaplings") have been found, representing several pterosaur families, including pterodactylids, rhamphorhinchids, ctenochasmatids and azhdarchids. All preserve bones that show a relatively high degree of hardening ("ossification") for their age, and wing proportions similar to adults. In fact, many pterosaur flaplings have been considered adults and placed in separate species in the past. Additionally, flaplings are normally found in the same sediments as adults and juveniles of the same species, such as the "Pterodactylus" and "Rhamphorhynchus" flaplings found in the Solnhofen limestone of Germany, and "Pterodaustro" flaplings from Argentina. All are found in deep aquatic environment far from shore.