Why Huge Dinosaurs Had Such Tiny Babies

A new study may explain many mysteries about dinosaurs, such as why enormous species had such small offspring, why non-flying dinos went extinct, and why today’s birds fly. The paper, published in the journal Biology Letters, emphasizes how mammals and birds -- but not non-avian dinosaurs -- were able to persist beyond a major extinction 65.5 million years ago. The large body size and egg-laying ways of dinos may have helped to do them in, along with hungry mammals. "The most successful (dinosaurs) were the very large ones that were able to escape the competition trap and replenish their numbers. After the mass extinction, they again tried to evolve large size, but to escape the competition trap they had to become multi-ton animals," lead author

  Daryl Codron told Discovery News.