Soft-Shelled Dinosaur Eggs
The paper was published in Nature along a separate study that argues that it wasn’t only ancient reptiles that laid soft-shell eggs — dinosaurs did too.
For years, experts believed dinosaurs only laid hard-shelled eggs, which are all that had been found.
But Mark Norell, curator of paleontology at the American Museum of Natural History, said the discovery of a group of fossilized embryonic Protoceratops dinosaurs in Mongolia made him revisit the assumption.
“Why do we only find dinosaur eggs relatively late in the Mesozoic and why only in a couple groups of dinosaurs,” he said he asked himself.
The answer, he theorized, was that early dinosaurs laid soft-shell eggs that were destroyed and not fossilized.
To test the theory, Norell and a team analyzed the material around some of the Protoceratops skeletons in the Mongolia fossil and another fossil of two apparently newborn Mussaurus.
They found chemical signatures showing the dinosaurs would have been surrounded by soft, leathery eggshells.
“The first dinosaur egg was soft-shelled,” Norell and his team conclude in the paper.
Norell’s findings may have implications for the fossil once named “The Thing” — which is now known as Antarcticoolithus, according to a review of the studies published in Nature.
They “could implicate some form of dinosaur as the proud parent,” wrote Johan Lindgren of Lund University and Benjamin Kear of Uppsala University.
“Let us hope that future discoveries of similarly spectacular fossil eggs with intact embryos will solve this thought-provoking enigma.”