Brows furrowed, he gazed through the microscope for what seemed like hours without saying a word. After I sought opinions on the identity of the red spheres from faculty members and other graduate students, word of the puzzle reached Jack Horner, curator of paleontology at the museum and one of the world’s foremost dinosaur authorities. Given that dinosaurs were nonmammalian vertebrates, they would have had nucleated blood cells, and the red items certainly looked the part, but so, too, they could have arisen from some geologic process unfamiliar to me.īack then, I was a relatively new graduate student at Montana State University, studying the microstructure of dinosaur bone, hardly a seasoned pro. As I sat in the museum that afternoon in 1992, staring at the crimson structures in the dinosaur bone, I was actually looking at a sign that this bedrock tenet of paleontology might not always be true-though at the time, I was mostly puzzled. The conventional wisdom holds that when an animal dies under conditions suitable for fossilization, inert minerals from the surrounding environment eventually replace all of the organic molecules-such as those that make up cells, tissues, pigments and proteins-leaving behind bones composed entirely of mineral. The bone slice was from a dinosaur that a team from the Museum of the Rockies in Bozeman, Mont., had recently uncovered-a Tyrannosaurus rex that died some 67 million years ago-and everyone knew organic material was far too delicate to persist for such a vast stretch of time.įor more than 300 years paleontologists have operated under the assumption that the information contained in fossilized bones lies strictly in the size and shape of the bones themselves. In fact, the spheres looked just like the blood cells in reptiles, birds and all other vertebrates alive today except mammals, whose circulating blood cells lack a nucleus. Each had a dark center resembling a cell nucleus. The tiny structures lay in a blood vessel channel that wound through the pale yellow hard tissue. Peering through the microscope at the thin slice of fossilized bone, I stared in disbelief at the small red spheres a colleague had just pointed out to me.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |