Ken Carpenter, curator of paleontology at the Denver Museum of Nature & Science, was rooting through a cabinet drawer at Yale University's Peabody Museum when he came across a fossilized tooth. And not just any tooth: The three-and-a-half-inch-long specimen, first found in Golden in 1874, then stashed at the Peabody, turned out to be a 67-million-year-old tooth from a Tyrannosaurex rex -- giving the Yale museum a nice display piece, and giving Colorado bragging rights for having made the earliest T. rex find.