The figure of the pterodactyl represents pretty closely that which is given to the dragons.

It is not impossible that they may have existed into the period which we call prehistoric, and that monsters far larger than any which we have yet discovered may have lingered until the time when man began to increase upon the earth, to spread over its surface, and to carve upon wood and stone representations of the most striking objects around him.

When the living pterodactyls had disappeared the memory of them was preserved; some new features were added, and the imagination went so far as to endow them with the power of belching forth smoke and flames.

Thus the dragon idea pervaded the minds of men, and instead of a natural animal it became a fabulous one.
"The fingers of the forelegs were of the ordinary dimensions, and terminated with crooked nails, and these were probably used to suspend themselves from trees.

When in repose it rested on its hind legs like a bird, and held its neck curving behind, so that its enormous head should not disturb its equilibrium.