Adam Britton wrote:
>Although I don't believe it's particularly important for crocs, it should be
>pointed out that a crocodile with its mouth closed actually has a pretty
>good (if not watertight) seal between the maxilla and the mandible. The
>interior of the mouth remains moist for some time if the mouth is kept
>closed (e.g.. with tape, when sedated), although I seriously doubt anyone has
>measured it objectively.
I think that this is very important for all crocodilians. (Theropod) Dinosaurs did not have this feature, instead, they had spaces between their maxillae (which were "V" shaped) and mandibles (which were "U" shaped). Theropods would have a large gap between the lower jaw and the upper. Therefore, lips would be required in dinosaurs to prevent desiccation.