The exceptionally preserved Protoceratops specimen includes six embryos that preserve nearly complete skeletons. Image credit: M. Ellison / American Museum of Natural History.
Posted on 06/21/2020 9:37:17 PM PDT by SunkenCiv
A team of paleontologists from the United States, Canada and Argentina has analyzed the fossilized eggs of two different non-avian dinosaurs, Protoceratops and Mussaurus, and found that the eggs resembled those of turtles in their microstructure, composition, and mechanical properties. They've also found that hard-shelled eggs evolved at least three times independently in the dinosaur family tree.
For many years there was scant fossil evidence of dinosaur eggs, and all known examples were characterized by thick, calcified shells -- leading paleontologists to speculate that all dinosaur eggs were hard-shelled, like those of modern crocodiles and birds.
"The assumption has always been that the ancestral dinosaur egg was hard-shelled," said study first author Dr. Mark Norell, chair and Macaulay Curator in the Division of Paleontology at the American Museum of Natural History.
"Over the last 20 years, we've found dinosaur eggs around the world. But for the most part, they only represent three groups: (i) theropod dinosaurs, which include modern birds; (ii) advanced hadrosaurs like the duck-bill dinosaurs; (iii) and advanced sauropods, the long-necked dinosaurs." ...
The researchers focused on the mineral and chemical compositions of the fossils, including a dark-colored halo surrounding the fossilized embryos.
"We looked for any residue of a protein eggshell membrane," said study co-author Jasmina Wiemann, a graduate student in the Department of Geology & Geophysics at Yale University.
"We essentially 'fingerprinted' a large number of modern and fossil samples to build a dataset of the overall molecular picture of the eggshell through time."
The scientists found that the early dinosaur eggs had a chemical residue that was non-mineralized -- meaning they were more like today's leathery turtle eggs, protecting their embryos with a soft outer covering.
(Excerpt) Read more at sci-news.com ...
The exceptionally preserved Protoceratops specimen includes six embryos that preserve nearly complete skeletons. Image credit: M. Ellison / American Museum of Natural History.
Turtles all the way down...
Modern lizard eggs are also rubbery-shelled.
Probably Helen Thomas' were as well.
They’re what dinosaurs made their purses out of.
I thought I remembered reading years ago that dinosaur egg shells were leathery...
Sunny side up, please.
Interesting!
The lack of mammals means no omelets for 100 million years. So do you want in scrambled, fried or poached?
Like SNAKE and TURTLE EGGS.........
So THAT’s what D&B stands for...........
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