The cache of well-preserved two-inch eggs stunned his colleague Dr. Kellner.
“If you were to tell me a year before that someone would find hundreds of pterosaur eggs at one spot I would have said ‘Yeah, yeah get out of here. Not even in your dreams,’” Dr. Kellner said. “But here we are.”
Pterosaurs laid soft eggs like snakes or lizards, not brittle ones like birds. The fossilized eggs found at the nesting ground look more like deflated balloons than eggs cracked for an omelet.
Dr. Kellner said it was also much more likely that pterosaurs laid their eggs in large nesting colonies near lake and river shores rather than in solitary nests high on cliffsides. He added that the large number of eggs they found suggested the pterosaurs returned to the nesting spot numerous times to lay their eggs.
Using CT-scanning, the team peered into the shells. Of the 215 eggs they found, 16 had embryonic remains, including one with partial wings and a toothless lower jaw. The team also discovered evidence that hatchlings had leg bones that were more developed than their forelimbs, suggesting the babies most likely crawled and were unable to fly. The team added that young pterosaurs were probably very reliant on their parents.
Denis Charles Deeming, a paleontologist from the University of Lincoln in England who wrote an adjoining article in Science about the findings, said he was surprised by the sheer number of eggs that were all collected together in one place. But he cautioned against making conclusions about the early lives and development of pterosaurs from the small number of embryos that the team found.
“They try to paint a picture of how these things worked, but the reality of it is that the evidence isn’t there,” he said.
Dr. Kellner said his team plans to uncover more pterosaur eggs, which may be hiding beneath the ones they already found. They hope to find more preserved embryos that will help unscramble the mystery.