The mass extinction event is when scientists believed a great meteor wiped all dinosaurs from the face of the Earth; however, were all dinosaurs vanished? It was determined that the age of dinosaurs ended between 65.5 and 66 million years ago but University of Alberta researchers found a dinosaur bone fossil in New Mexico and found out that it was a femur bone of a hadrosaur as being only 64.8 million years old. That means this dinosaur was alive about 700,000 years after the mass extinction. To find this fossil, the researchers used a new direct-dating method called U-Pb (uranium-lead) dating that tells the researchers the age of the fossil bone and the type of food the dinosaur eats. During this dating method a laser beam unseats minute particles of the fossil, which then undergo isotopic analysis. Living bones contain a small amount of uranium, however,during fossilization (less than 1000 years after death) bone is enriched in elements like uranium. The uranium atoms in bone decay spontaneously to lead over time and once fossilization is complete the uranium-lead clock begans.
