More than 200 dinosaur eggs have been discovered in China, including 16 that hold embryonic remains.
The eggs, from a flying reptile known as a pterosaur, were discovered by researchers working in the Turpan-Hami Basin in northwestern China during a 10-year span ending in 2016.
The cache shines new light on the development and nesting behavior of pterosaurs (Hamipterus tianshanensis), which were believed to have a wingspan of up to 13 feet, and likely ate fish with their large teeth-filled jaws.
Pterosaurs lived during most of the Mesozoic Era: from the late Triassic to the end of the Cretaceous, some 228 million to 66 million years ago.
The discovery, announced through the journal Science, sparked debate about whether the creatures could fly as soon as they hatched, according to National Public Radio.
There had been previous theories that hypothesized that they could, but the paper suggested differently. The research team found that the pterosaur’s hind leg bones were more developed than the wings at the time of hatching, and none of the embryos were found with teeth.
“Thus, newborns were likely to move around but were not able to fly, leading to the hypothesis that Hamipterus might have been less precocious than advocated for flying reptiles in general … and probably needed some parental care,” the paper stated.
Science added that it cautioned against drawing firm conclusions about how the animal moved immediately after hatching because it’s hard to pinpoint just how close the embryos were to hatching.
One single sandstone block held at least 215 well-preserved eggs that have mostly kept their shape, with 16 of those eggs featuring embryonic remains.
The massive discovery does not appear to include a nest, as the eggs had been moved from the place they were originally laid and may have been carried by water after a series of storms hit the reptiles’ nesting ground.
The fossils in the area are so plentiful that scientists refer to it as “Pterosaur Eden,” said Shunxing Jiang, a paleontologist at the Chinese Academy of Science’s Institute of Vertebrate Paleontology and Paleoanthropology.
“You can very easily find the pterosaur bones,” he said, adding that they believe dozens more eggs might still lie hidden within the sandstone.
Prior to this discovery, only five other well-preserved pterosaur eggs had been found in this area and one had been found in Argentina, according to NPR.
“The 16 fossilized embryos are at different stages of growth, revealing new information about how the reptiles developed,” NPR added. “None of the embryos are complete, the paper states, and the scientists used computed tomography scanning to view what was inside.”
(Artist’s depiction of pterosaurs, which lived between 228 million and 66 million years ago.)