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Sexual Identification of A Rex Fossil
Rollie Hawk writes "The Tyrannosaurus rex has long been the darling of science fiction dinosaurs and has one of the most well-known skeletal designs among extinct creatures. But while even the most casual dinosaur enthusiast can identify the T. rex, until recently the sex of individual specimens was not discernable. Though dinosaurs are most known for their traits shared with modern reptiles, it is their kinship with birds that has finally revealed the sex of a T. rex fossil. To prepare for egg production, female birds develop a thick layer of medullary bone in their long bones, which acts as an extra source of eggshell calcium. According to Dr. Mary H. Schweitzer of North Carolina State University, the 'tyrant lizard king' appears to do the same thing. She explains that 'dinosaurs produced and shelled their eggs much more like modern birds than like modern crocodiles.'"
This is a cool achievement, but it does have limitations: (from the article)
"This discovery will not enable paleontologists to determine the sex of all dinosaurs because medullary bone is present only during the egg-laying cycle. But when present, it at least enables scientists to say that a particular example is female.
Not every museum may want to check the sex of its specimens because it requires cutting a long bone in half, said Horner, a co-author of the paper with Schweitzer.
Even then, finding medullary bone is a long shot, Schweitzer said. First the dinosaur has to be an ovulating female. It also has to die before it has finished laying eggs and has to be fossilized. Finally, that fossil has to be found by humans."
Unfortunately, this only means that a few specimens of them can be identified. It says that it's a damaging procedure, can only be used to determine femaleness and also, only works in a few cases.
It also might be interesting to know that this particular dinosaur specimen was also the first specimen they were able to recover soft tissue from a dinosaur.
"Real programmers don't comment their code. If it was hard to write it should be hard to understand."
We need to send Steve Irwin back in time, then we would learn all about dinosaur sex when he tries to molest them and gets eaten, that would have to be the best episode of the croc hunter ever.
link is here: http://www.npr.org/templates/story/story.php?story Id=4677825
I heard about it this morning. It sounds better over coffee.
Damn. . .every program I hear on WBUR (NPR) has been showing up on slashdot three days later. . .
Then again, if I were a male T-Rex, my DNA would have been all over the place. Nudge nudge.
That's understandable. They didn't have kleenex tissues back then.
"I've got more toys than Teruhisa Kitahara."
...is that no one thought of this before now.
Scientists have long known that dinosaurs have a kinship with birds even though they share traits with modern reptiles and many strides have been made in the field as a result of that knowledge.
This news clearly has to be one of the finer examples we have where almost everyone is compelled to say "Damn, why didn't I think of that!"
Heh... I thought they gained the ability from a writer who needed to move the plot along.
Wow. That's scary. A governing body to determine what is worth studying and what isn't?! The purpose of expanding knowledge is to expand knowledge.
No, we absolutely wouldn't be. The problem is that nobody knows what is "worthwhile" and what isn't. It's obvious in hindsight, for example, that studying aerodynamics to learn how to make a workable airplane was a productive application of science, but at the time many people thought it was a complete waste of time (i.e. how could anything heavier than air possibly fly?). If science had a "governing body" that ordered the Wright brothers (etc) to work on "something more worthwhile", would the airplane ever have been invented?
On a different topic: shouldn't this specimen properly be called a "T. Regina"?
I don't care if it's 90,000 hectares. That lake was not my doing.
Well, sort of--T. rex is a Saurischian, or lizard-hipped dinosaur, as are modern birds. (Actually, they've reverted to the other dominant hip type, which is why other dinosaurs are called Ornithischians, or bird-hipped.) Except that would be forward-and-to-one-side compatibility. Remember, kids, T. rex is a Coelurosaur, not a Carnosaur! Join our letter-writing campaign to correct two diagrams at the American Museum of Natural History today!
Even then, finding medullary bone is a long shot, Schweitzer said. First the dinosaur has to be an ovulating female. It also has to die before it has finished laying eggs and has to be fossilized. Finally, that fossil has to be found by humans.
That last part is certainly a long shot for any bones lying undiscovered in a museum somewhere.