If new findings by Robert Reisz, a palaeontologist at the University of Toronto, are to be believed, then some things we've come to assume about dinosaurs might need some amending.
Specifically, when it comes to their lips, or lack thereof (via Utoronto.ca). The findings were presented at a conference at the University, where Reisz said: "When we see dinosaurs in popular culture, such as in the movie Jurassic Park, we see them depicted with big teeth sticking out of their mouths." When you compare a Tyrannosaurus Rex to a Velociraptor, for example, the T-Rex is all teeth, yet the Velociraptor actually has scaly lips that cover theirs.
It turns out the Velociraptor might be closer to reality. Reisz continued: "Lips help to protect teeth, in part by helping to enclose them in a moist environment where they won't dry out. Crocodiles, which spend their time submerged in water, don't need lips for protection. Their teeth are kept hydrated by an aquatic environment."
In most cases, the dinosaurs would have needed lips to protect their teeth, as the majority of them weren't water dwelling creatures. They would have had scaly lips, just like reptiles such as the monitor lizard.
"It's also important to remember that teeth would have been partially covered by gums. If we look at where the enamel stops, we can see that a substantial portion of the teeth would be hidden in the gums. The teeth would have appeared much smaller on a living animal." Reisz concluded: "In popular culture, we imagine dinosaurs as more ferocious-looking, but that is not the case."
Granted, even with lips they aren't necessarily warm and cuddly, but this does change how they are often depicted in film.