Are the TV/movie portrayals of pterosaurs scientifically accurate?
This is relative. What is considered scientifically accurate in the present may have been brushed off in the past as nonsense or inaccurate. That early Hollywood portrayals of pterosaurs depicted them as dull-colored, scary, weak flyers is partly a result of the conventional thought pervading at that time. Certainly it wasn’t in vogue at the time to depict pterosaurs as they are done so today. Hence, by the thinking of the time, pterosaurs graced the screens as they were thought to have lived.
