A MARTÍNEZ, HOST:
Good morning. I'm A. Martínez. Imagine a T. rex. Now think about its mouth. You probably imagine lots of scary-looking teeth. But research suggests that, contrary to popular belief, the T. rex did not have rows of exposed teeth. It had lips that covered those teeth. Some scientists disagree with this hypothesis and insist that the T. rex is lipless. But a T. rex with lips just seems so much more kissable? It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.