In their book, All Yesterdays: Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals, Darren Naish, C.M. Kosemen, and John Conway hypothesise that a lot of paleoart is wrong! They claim that current artists are relying too heavily on the skeleton alone, and aren’t taking into account body coverings, soft tissues or muscle structures.
The book, illustrated by
Scott Hartman, gave some depictions of modern day animals drawn “shrinkwrapped” (going by their bones alone without accounting for the soft tissue, fat, etc.).
Iguana as a mammal