Scientists for a long time have believed that the color of bird eggs was an evolutionary event unique to those animals. Some birds lay eggs in open nests, as opposed to cavities. Such nests expose eggs to predators. Color was thought to have evolved to offer eggs camouflage protection.

Not so, according to recent research on dinosaur eggs. Eggs probably laid by some type of oviraptor 66 million years ago have been found to contain pigment molecules similar to that of modern bird species. These are mostly blue-green colors.

Oviraptors were bipedal dinosaurs, two legs for mobility, two other appendages that became wings.

The study was made by researchers at Yale University, the American Museum of Natural History, and the University of Bonn. It was published in the journal Nature.

"This completely changes our understanding of how egg colors evolved," said the study's lead author, Jasmina Wiemann.

"For two centuries, ornithologists assumed that egg color appeared in modern birds' eggs multiple times, independently…"

When dinosaurs began to build open nests they needed the same camouflage protection needed by modern nesting birds, the study explains. Evolution favored color and patterns of spots and freckles, traits that continue today.