Some of the soft-shelled eggs that the team analyzed belonged to Protoceratops (right), a plant-eating dinosaur that lived around 75,000 years ago in what is now Mongolia. Whether the chicken or the ...

Since the time of Aristotle, humans have stood amazed by birds' dazzlingly colorful eggs, which range from creamy hues to the deepest reds, blues, and greens. But long before our love of robin's-egg ...