When scanning the Dino-data site for the Paul Sereno interview, I spotted the tyrannosaurus bust on the home page. I noticed it had large pouches of flesh either side of it's jaws similar to the ones crocodiles and alligators have. I'm assuming these pouches are for muscles that close the jaw - correct me if I'm wrong. Now according to the article in last month's Scientific American, it said that T-Rex's biting strength way surpassed that of a lion or a wolf but was not much larger than a crocodile's. Given that T-rex had a considerably larger mouth than most (all?) crocodiles, would it need such enormous pouches?