The embryo egg was first found by a Chinese farmer at a riverside in the Henan province of China. It had a 0.07-inch shell and was almost the size of a tennis ball. Most fossil eggs are not identifiable to a specific species, however, this egg was different. “This is actually the first time that [fossil] turtle eggs or a nest really could be attributed to a particular turtle,” stated Darla Zelenitsky, an Associate Professor of Paleontology at the University of Calgary. The egg was ascribed to the Nanhsiungchelyid turtle which existed during the late Cretaceous period.
The egg was a “really cool specimen” according to Daniel Lawver, a researcher at Stony Brook University’s School of Medicine. Unlike other turtle fossil eggs with thin casings, this egg had a thick and water-retaining shell and was therefore hardened enough to fossilise. Paleontologist Jordan Mallon, from the Canadian Museum of Nature, believed this evidence concluded the Nanhsiungchelyid turtle was land-dwelling.
This was further supported by a study in the journal Proceedings of the Royal Society B, titled “A Large and Unusually Thick-shelled Turtle Egg with Embryonic Remains from the Upper Cretaceous of China”. Here, the species was classified as terrestrial. The egg also helped trace the history of a dinosaur age species and pinpointed the number of eggs Nanhsiungchelyid female turtles normally laid (about 15 to 30). Additionally, further research into the embryo fossil found the prehistoric turtles were most likely 1.6 metres long in order to lay eggs－ almost the size of a human! They also lived in arid areas but laid eggs in moist soil.
A micro-CT scan conducted on the embryo showed it to be 85% developed, having tried to hatch, but unfortunately failed. However, the additional information obtained from this rare find has advanced science to the next level and unravelled more discoveries about the dinosaur age.