[Fred Nerks]

...Do you disallow the possibility that those depictions may be the result of preistoric people having stumbled onto fossil remains of the same animals we've discovered?

And thus, the griffin? Interesting idea. Fossil of a winged mammal?

[tacticalogic]

And thus, the griffin? Interesting idea. Fossil of a winged mammal?

Or simply an artist's active imagination. What's your basis for drawing the conclusion that it is more likely that the drawing was from direct observation of a living animal, and not from an artist's rendering of an animal from observed fossils or that it was an invention of the artist's imagination?

What evidence leads you to believe that one possibility is reasonable, and the other two not?