“We screened through lots of eggshells, and one day had a positive result for these oviraptor eggs. “I was originally taught that all the weird colors you can get in fossils, like the blueish-green hue, may be due to mineral precipitation,” Wiemann says. Millions of years ago, the eggs would likely have been a greener color, Wiemann says, perhaps similar to eggs laid by Australia’s ground-nesting emus and cassowaries today, which blend in well with the surrounding vegetation. Using chemical analyses, they were able to detect traces of two pigments, biliverdin and protoporphyrin, commonly found in modern bird eggs.
This made the scientists wonder if the eggs could harbor any of their original color. While many fossil dinosaur eggs are black or brown due to the fossilization process, the eggs of Heyuannia have an unusual blueish tint to them. Commonly found in the fossil beds of eastern China, Heyuannia was a parrot-beaked, feathered species that walked on its hind legs and would have been about five feet long. Now, a study by Wiemann and her colleagues in Germany and California pushes back the origins of colored eggs at least as far as the Late Cretaceous.Īs they report in the journal PeerJ, a species of oviraptor called Heyuannia huangi had eggs that were colored deep blue-green. According to paleontologist and National Geographic grantee Jack Horner, it also stands to reason that dinosaurs had similar courting behaviors as today’s birds. “Once the idea that colored eggs evolved in birds and were a trait of modern birds had been suggested, no one thought about it again or dared to ask if dinosaur eggs had been colored,” Wiemann says.įossil research has shown that birds and dinosaurs shared behaviors such as brooding and nest building. (Also find out the surprising link between eggs shape and flight in birds.) For this reason, ornithologists had long assumed that colored eggshells evolved solely in some groups of birds after nonavian dinosaurs had died out. Many birds lay white, unpigmented eggs-as do all lizards, turtles, crocodiles, and the only known egg-laying mammals, the platypus and the echidna. The discovery overturns a common assumption: “Everyone thought dinosaur eggs were white,” says study coauthor Jasmina Wiemann at Yale University.
Looking at fossil eggshells from China, researchers have found evidence that an omnivorous, ostrich-like dinosaur laid clutches of blue-green eggs, potentially helping to camouflage them in open nests dug into the ground. Robins may be famous for their beautiful blue eggs, but ancient feathered dinosaurs beat them to the punch.
0 kommentar(er)
