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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.'"

3 of 105 comments (clear)

  1. Cool, but limitations. by Xeroc · · Score: 5, Informative

    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."
  2. Re:Jurassic Park by Anonymous Coward · · Score: 3, Funny

    Heh... I thought they gained the ability from a writer who needed to move the plot along.

  3. Re:This is what makes me worry about science. by Jeremi · · Score: 3, Insightful
    We would be better off if all science had a governing body that said which studies are worthwhile


    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"?

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