So far, today has been a day that was been predominated by news related to dinosaurs. We here at The Monitor Daily have so far today written about a how the tyrannosaurus rex reached its position as king of the dinosaurs, about how Chilean scientists developed a chicken with dinosaur legs, and now I’m going to write about dinosaur genders.
Revealing a not-quite-secret paleontologists have been keeping since forever, a team of researchers from North Carolina explained how a Tyrannosaurus Rex fossil can solve the gender mystery involving dinosaurs. What is the mystery, you may ask? Well, experts aren’t really sure when they’re dealing with a male fossil or a female one.
But how is that possible? With all the years looking into how these creatures lived, and with all of the combined experience of paleontologists all over the world, how can it be that difficult to tell a dinosaur’s gender? Well, according to Lindsay Zanno, the study’s co-author and head of the North Carolina Museum of Natural Sciences’ Paleontology Research Lab, the answer is quite simple.
It’s a dirty secret, but we know next to nothing about sex-linked traits in extinct dinosaurs. Dinosaurs weren’t shy about sexual signaling, all those bells and whistles, horns, crests, and frills, and yet we just haven’t had a reliable way to tell males from females. Just being able to identify a dinosaur definitively as a female opens up a whole new world of possibilities.
So, if it’s so difficult to identify a dinosaur by its gender and the fossilized T-Rex wasn’t found with a fetus, how exactly was the tam able to determine that it was female? By using a pregnancy indicator common in the last remaining dinosaurs – birds.
The medullary bone is a bone common in most birds, but one that is quickly disposed of and then reacquired under certain conditions. When laying eggs, the spongy looking bone is formed inside the birds’ femur. It serves as a strong source of calcium, so that the animal can build strong shells for its eggs without it having to deplete the calcium from its own bones.
The bone gets formed quickly right before the animals start laying eggs, and it is completely used up by the time they are done. So, the bone is only present in the animals for somewhere around two to four weeks. This means that the team had a hugely lucky break in determining the animal’s gender.
Of course, now that they know that the fossils they have in their possession are those of a female, the team is going to have an easier time looking for ways they could differentiate the extinct animals’ sexes.
Dinosaurs pushed the limits of what life on this planet could do.
This is how Zanno concluded, rephrasing what was perhaps best put as “Life, uh… finds a way”.
Image source: Pixabay