World / Science & Health

Colored bird eggs traced to dinosaurs


Birds have more in common with dinosaurs than previously thought — they inherited colored eggs directly from their scaly ancestors, according to research released Wednesday.

The evolutionary link between dinosaurs and birds has been recognized for centuries, but ornithologists long believed that birds evolved their colored eggs several times over history, mimicking local hues to help their eggs blend in.

Birds are the only creatures known today to lay colored eggs, and do so using only two pigments: red and blue.

Researchers analyzed 18 fossil samples of dinosaur eggshells in the U.S., Taiwan and Switzerland, using lasers to test for presence of the same pigments.

They found them in eggs from dinosaurs including velociraptors that lived in what is now Mongolia around 75 million years ago.

“This completely changes our understanding of how egg colors evolved,” said Yale University paleontologist and lead study author Jasmina Wiemann.

She said her team believes the dinosaurs evolved egg color to protect their offspring from predators when they started building open nests — a trait passed on to birds, which nearly always leave their eggs exposed before hatching.

“Color eggs have been considered a unique bird characteristic for over a century,” said Mark Norell, the Macauly curator of paleontology at the American Museum of Natural History.

“Like feathers and wishbones, we now know that egg color evolved in their dinosaur predecessors long before birds appeared.”

The study was published in the journal Nature.