The Croods is not “historically inaccurate”.
I see that word used a lot on the Croods for some reason.
Its not trying in the slightest to represent actual events that took place on earth. It merely uses concepts like continental drift, and takes a LOT of artistic license. For something to be “inaccurate” it needs to be actually attempting to represent a real thing. The Croods is not.
There are flying turtles.