Dinosaurs have pregnancies as premature as age 8, far before they attain their maximum adult size. Researchers initiate medullary bone,the same tissue that allows birds to grow eggshells, into two new dinosaur specimens: the meat eater Allosaurus as well as the plant eater Tenontosaurus. It's too been found in Tyrannosaurus rex. The discovery allowed researchers to find the age of these pregnant dinosaurs were at 8, 10 and 18. These put forward that the mortal reached sexual maturity in advance. Dinosaurs grow up fast but only alive three to four years in adulthood. Medullary bone is only approximately for three to four weeks in females who are reproductively mature. The research too offers more confirmed that dinosaurs were less like reptiles and more like birds. While dinosaurs had young before adulthood, their early on sexual maturity was more a function of their tremendous size than some anatomical similarity to crocodiles.

Refer: http://www.citizen-times.com/apps/pbcs.dll/article?AID=/20080120/
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