Building a dinosaur from a chicken

Paleontologist Jack Horner has spent his career trying to reconstruct a dinosaur. He's found fossils with extraordinarily well-preserved blood vessels and soft tissues, but never intact DNA. So, in a new approach, he's taking living descendants of the dinosaur (chickens) and genetically engineering them to reactivate ancestral traits — including teeth, tails, and even hands — to make a "Chickenosaurus".