Leathery dinosaur eggs had to be laid somewhere moist, because they needed external liquid to provide water to the growing baby dino (as most reptile eggs still do today), while the bird egg's solid exterior created a protective wall around the water already inside the egg. But there are thousands of species of birds, each with their own unique eggs—so when did the chicken egg become synonymous with egg, to the point where most of us have never tasted any other kind? The Great Egg Taste Test: Quail eggs, Andean blue eggs, and dark brown Marans eggs.