Scientists found a pregnant T-Rex (Tyrannosaurus rex), and this can help with the study of the evolution of egg-laying as well as on gender differences in the dinosaur.

The remains could also contain the DNA of all dinosaur fossils. The fossil was discovered long back in 2005, but just now, experts came to know that the T.Rex was a mother-to-be when it took its last breath.
This new finding is expected to be a breakthrough in the field of paleontology as most of the times; experts fail to determine the exact gender of dinosaurs.

The team from North Carolina State University and the North Carolina Museum of Natural Sciences published its findings Tuesday in the journal Scientific Reports.

Researchers have found the medullary bone in the femur of the fossil, and it helped them to make a conclusion that the T-Rex is pregnant. Medullary bone is only present in female birds — which are related to dinosaurs — just before and during egg-laying.

“It’s a special tissue that is built up as easily mobilised calcium storage just before egg-laying,”.

“The outcome is that birds do not have to pull calcium from the main part of their bones in order to shell eggs, weakening their bones the way crocodiles do.”

Crocodiles are the closest-living relatives of dinosaurs.

“Medullary bone is thus present just before and during egg-laying, but is entirely gone after the female has finished laying eggs,”Dr Lindsay Zanno, the assistant research professor of biological sciences at North Carolina State University, said.

Cross-section-of-T-rex-bone

Cross section of T-Rex bone

“We have some evidence that fragments of DNA may be preserved in dinosaur fossils, but this remains to be tested further.” said Dr. Zanno.