Published: Fri, November 02, 2018
Science | By

Coloured bird, dinosaur eggs in same evolutionary basket

Coloured bird, dinosaur eggs in same evolutionary basket

Though most of us are familiar with blue-speckled robin's eggs or golden-brown chicken eggs, the sheer range of colors and patterns on bird eggs is incredible: they can be brick-red, marbled in patterns that look like the surface of the Moon, or covered in squiggly lines like a Jackson Pollock painting.

An extensive analysis of 12 fossilised dinosaur eggshells from Asia, Europe, South and North America have detected a duo of pigments present in the eggs of colourful birds' eggs of a group called eumaniraptorans, which consists of well-known carnivores like Velociraptor and the small feathered dinosaur ancestors of birds.

In spite of their diversity, bird eggs derive their color from just two pigments: protoporphyrin, which produces a reddish-brown color, and biliverdin, which creates blue and green.

Hauber offered three other reasons, in addition to camouflage, why birds have colorful eggs: One, pigments can act like a parasol or sunscreen, protecting the embryos within from too much heat.

Whereas, all other dinosaurs produced plain white eggs, making the evolutionary egg colour of eumaniraptoran dinosaurs more special. "Our study fundamentally changes our understanding of egg colour evolution, and adds colour to dinosaur nests in the real "Jurassic World". But because egg color in birds is associated with complex nesting behaviors, this-along with existing fossil evidence-signals such advanced parental care may have also taken place among dinosaurs.

To find out whether colored dinosaur eggs shared an evolutionary origin with those of birds, Wiemann and her colleagues amassed well-preserved fragments of fossil eggshell from 15 Cretaceous era dinosaurs and extinct birds, as well as eggshell from living chickens, terns, emus, and alligators.

According to researchers at Yale, the American Museum of Natural History, and the University of Bonn, birds inherited their egg color from non-avian dinosaur ancestors that laid eggs in fully or partially open nests. They all belong to the group of Eumaniraptora, which will include modern birds.

People who are accustomed to see the eggs alone the hen, it is hard to imagine how diverse is their colouring from other birds, from chocolate brown to emerald green, from brick red to bright blue.

Not only were dinosaurs the masters of the land and the sea, but they were also the masters of color, a new study shows.

"We infer that egg color co-evolved with open nesting habits in dinosaurs", Wiemann said.

But that was one dinosaur.

Now the researchers have analyzed egg shells from more.

If you're interested in all the practical advantages of speckled and brightly colored eggs, check out this article. "We tried to cover the major branches of dinosaurs to get a good idea for all non-avian dinosaurs", she says.

Traditionally, dinosaurs were thought of as reptilian-style breeders that dumped their eggs and left. This is an artist's impression of the oviraptorid dinosaur Huanansaurus ganzhouensis. And the presence of speckling raises the possibility there may have been nest parasites long before the appearance of birds - the cuckoo dinosaur.

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