Some dinosaurs had exquisite eggs with colors, spots, speckles

WASHINGTON (Reuters) – Some dinosaurs have laid colorful, speckled and speckled eggs with exquisite blue and brown hues, scientists said Thursday during a discovery that blurs the notion that such exceptional traits are native to the world. ;birds.

An analysis of 12 fossilized dinosaur egg shells from Europe, Asia, North America, and South America revealed the presence of the same two pigments present in the colorful bird eggs in a group of dinosaurs called eumaniraptorans, which includes well-known carnivores like Velociraptor and the small ancestors of the feathered dinosaur of birds.

"We discovered that the color of the egg was not a unique feature of our modern birds, but that it had evolved within their non-avian ancestors, the dinosaurs," said the Yale University paleontologist, Jasmina Wiemann, who led the study published in the journal Nature. "Our study fundamentally changes our understanding of the evolution of egg color and adds color to the dinosaur nests of the true" Jurassic world. "

For example, the predator Deinonychus with claws had a blue egg with brown spots and Oviraptor, similar to a bird, known for its toothless bill, had dark blue eggs.

The birds evolved from eumaniraptoran dinosaurs to the Jurassic era. Archeopteryx, the first known bird, lived in Germany about 150 million years ago.

The Eumaniraptorans, which are part of the larger assemblage of two-legged meat-eating dinosaur theropods, were generally small and resembled birds, covered with a colorful plumage. They included predators up to 9 meters long and as small as a domestic cat, but did not include behemoths such as Tyrannosaurus rex and Giganotosaurus.

Egg color confers an evolutionary advantage to the dinosaurs whose eggs are exposed, instead of burying them as alligators and turtles do, partly by camouflaging themselves to protect themselves from egg-eating predators, said the researchers.

All of the other dinosaurs studied produced white eggs, indicating a single, evolutionary origin of egg color in eumaniraptoran dinosaurs and passed on to their offspring of birds.

In the eumaniraptorans, the researchers found a blue-green pigment called biliverdin and a red-brown pigment called protoporphyrin IX, structurally integrated in the crystalline matrix of the shell, as in birds.

"Some were uniform in color," said paleontologist and co-author of the study, Mark Norell, of the American Museum of Natural History in New York. "Some have been spotted and speckled. It was like in live birds. The egg of the merle is uniformly blue, but that of the quail is stained and speckled. "

According to Norell, other traits that were supposed to have origins in birds, such as feathers and triangles, were also inherited from their dinosaur ancestors.