Gizmo

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.'"http://science.slashdot.org/article....55217&from=rss