Tuesday, January 15, 2008

Teenage pregnancy in dinosaurs

Congrats to Sarah and Andrew!!

Dinos sexually mature by 8, research shows

WASHINGTON (AP) -- -- Adolescent pregnancy isn't a modern invention, it occurred in dinosaurs millions of years ago.

Medullary bone, a type of tissue present in modern birds when they are developing eggs, has been found in three dinosaur fossils, researchers report in Monday's online edition of Proceedings of the National Academy of Sciences.

The dinosaurs were aged 8, 10 and 18, indicating they reached sexual maturity earlier than previously thought.

In modern birds, medullary tissue lines bones for only a few weeks when they are producing eggs and is then reabsorbed. Finding it in dinosaurs, which are believed to be the ancestors of birds, sheds light on their reproduction also.

Most dinosaurs lived to only about age 30, though some reached 60, the researchers said.

The study was done by Sarah Werning, a graduate student at the University of California, Berkeley, and Andrew Lee, also a graduate student at Berkeley when the work was done. Lee is now a postdoctoral student at the Ohio University College of Osteopathic Medicine.

"This is an exciting finding, because age at sexual maturity is related to so many things," the students' adviser, said Kevin Padian, a professor of integrative biology and a curator in UC Berkeley's Museum of Paleontology.

Werning said in a statement that pinpointing the age of reproductive maturity "opens up so many complementary avenues of dinosaur research. You can talk about dinosaur physiology, lifespan, reproductive strategies. And you could use this technique to look at all kinds of extinct animals."

The medullary bones examined by Werning and Lee came from the meat-eater Allosaurus and the plant-eater Tenontosaurus. It's also been found in Tyrannosaurus rex, they said.

The research was done by the Geological Society of America, the Paleontological Society, the University of Oklahoma Graduate Student Senate, the Jurassic Foundation and U. C. Berkeley's Department of Integrative Biology.

Lee, A. H. & Werning, S. 2008. Sexual maturity in growing dinosaurs does not fit reptilian growth models. Proceedings of the National Academy of Sciences 105, 582-587.



Unknown said...

Its regarding with pregnancy and adolescent pregnancy isnt a modern invention but it is concerned with dinosaurs too. They reached maturity earlier than expected. So, in my opinion pregnancy not only occurs in women but also in animals too.

ReBecca Hunt-Foster said...

That is a fact. I don't think the paper disputes it or claims it is new.

Anonymous said...

Yeah! Its absolutely true that Teen Pregnancy is common in animals too such as in dinosaurs. Its pretty sure that pregnancy not only occurs in womens but also in animals too. I suggest that animals are also gifted by god so they have every right to become pregnant.