A pregnantTyrannosaurus rex has been found, shedding light on the evolution of egg-laying as well as on gender differences in the dinosaur. The remains also could contain the holy grail of all dinosaur fossils: DNA.
"Yes, it is viable," Lindsay Zanno advised Discovery News, regarding genetic fabric that can be found in this in addition to similar dinosaur unearths. "We have some evidence that fragments of DNA can be preserved in dinosaur fossils, but this remains to be examined similarly."
What has been confirmed so far is that theT. rex, which was found in Montana and dates to 68 million years ago, retained medullary bone that reveals the individual was pregnant. Medullary bone is only present in female living dinosaurs, i.e. birds, just before and during egg laying. It's this type of bone that could retain preserved DNA.
Zanno is an assistant studies professor of biological sciences at North Carolina State University, wherein she is also head of the North Carolina Museum of Natural Sciences' Paleontology Research Lab and is curator of paleontology. She defined that medullary bone lines the marrow cavity of the lengthy bones of birds.
"It's a unique tissue this is built up as without difficulty mobilized calcium storage simply earlier than egg laying," she said. "The outcome is that birds do now not have to tug calcium from the primary part of their bones in order to shell eggs, weakening their bones the manner crocodiles do."
Crocodiles, she stated, are the nearest dwelling household of dinosaurs.
"Medullary bone is accordingly gift just before and at some stage in egg laying, but is absolutely long past after the woman has finished laying eggs," she said.
Early on, Mary Schweitzer suspected that medullary bone was present in the tyrannosaur remains, and was able to confirm her suspicions after she, Zanno and their team conducted a chemical analysis of theT. rex's femur.
The material, discovered to be consistent with recognised medullary tissues from ostriches and chickens, contained karatan sulfate, a substance no longer found in any other bone sorts.
"This evaluation lets in us to determine the gender of this fossil, and gives us a window into the evolution of egg laying in contemporary birds," Schweitzer said.