The eggs of amniotes - mammals, reptiles and birds – come in a remarkable variety of shapes and sizes. Evolutionary biologists have now addressed shape variety in terrestrial vertebrates' eggs, ...

The evolution of the amniotic egg—complete with membrane and shell—was key to vertebrates leaving the oceans and colonizing the land and air. Now, 360 million years later, bird eggs come in all shapes ...

It’s a mystery that goes back to the days of Aristotle, flummoxing biologists and mathematicians for centuries: Why do birds’ eggs come in so many different shapes and sizes? Why are owl eggs almost ...