Dinosaurs' egg-laying may have left them vulnerable to extinction when disaster struck.
The bigger the egg, the thicker the shell, but growing embryos need access to outside air. Therefore, egg size is necessarily limited.
Because of this fixed egg size, huge adult dinos began their lives as tiny babies. For example, Titanosaur newborns were 2,500 times smaller than their parents who at full-size weighed-in at 4 tons. In comparison, elephant calves are only 25 times smaller than their...Full Story