That worldwide coolness may have eliminated the dinosaurs by causing their eggs to hatch out all males or all females. Crocodilians and turtles share a special reproductive trait that is not found in any other living group of reptiles. Hotter conditions produce females in most turtles, and males in crocodilians. Hatched under lower temperatures, turtle eggs yield mostly males and crocodile eggs females . . Female turtles are larger than males . .
Male crocodilians are the larger sex . .
The top layer of eggs all developed into males, the middle layers produced a 50-50 ratio of sexes, and the bottom layers all hatched into females. It is also of interest that a majority of the larger dinosaurs were vegetarians, and many of the carnivorous dinosaurs preyed upon other dinosaurs. Dinosaurs were mostly vegetarians, despite their enormous size and decidedly carnivorous appearance. One exception was the mammoth Tyrannosaurus rex, which apparently ate other dinosaurs. The sudden extinction of the dinosaurs is another evidence of that worldwide event.