[Raynor]

Originally Posted by skip spence

The tendency among artists seems to be guana/dinosaur-like creatures that walk upright with strong legs even though Tolkien clearly described long and slithering serpent-like dragons.

That's.. a matter of contention (emphasis added):

Originally Posted by Tolkien, St . Andrews, and Dragons, page 9

The original impression of The Hobbit in 1937 had contained no colored pictures, but the second English impression of the same year and the first American edition in 1938 included five colored pictures by Tolkien, one of which was entitled “O Smaug, the Chiefest and Greatest of Calamities,” Bilbo Baggins’s words to the dragon in chapter 12—an illustration now more familiarly known as Conversation with Smaug and completed by Tolkien in July 1937.

In this familiar picture we see the dragon lying on his heap of treasure, with his belly toward the top of the pile, so that he is lying curled downwards, with his head resting on the hoard, smoke issuing from his nostrils and his ears pointed and alert, his right clawed foot extended.