Sure, maybe we can't say for sure that corythosaurs used their crests to communicate, though it's very reasonable to assume so. But you can't make a kid's show and qualify every single statement with disclaimers. And heck, when I was a kid everything I read or watched about dinosaurs stated conjectures as facts. The important part: it's a really nice looking show that has a good chance of getting tykes hooked on science. And stating a theory like that of the corythosaur's crests plants a seed that gets kids thinking about evolutionary adaptations. The song at the end of the clip is pretty shrill, but I do like how the theme song harkens back to the train songs that made up such a substantial portion of early rock and roll. Nice touch. Some of the folks here have good taste.
Also on the kid's entertainment front: They Might Be Giants is back with a new album and DVD for kids called Here Comes Science. It includes a tune called "I'm a Paleontologist." As an old school TMBG fan, I wouldn't count it among their golden classics, but what the heck. Good on 'em for writing it. Kids should dig it heartily. Read about it at Dinosaur Tracking.
Have a hell of a weekend. Now. Go.