Proof By Illustration: The Case of the (un)feathered Theropod

Images have power.

Every news outlet in the world knows it. Photographs, cartoons, sketches, whatever–all have been and continue to be used to illustrate articles. Get the right image, and the story writes itself. And more often then not, the story that gets written has more to do with the image then the facts of the case. Ask any Pulitzer Prize winning photographer; the pictures that win are the ones that confirm, in some way, an essential story we tell ourselves. People remember the photos and illustrations that accompany an argument far better then the argument itself. If you can show it, then to some extent you have proved it.

There’s a logical term for this: it’s called  ”Proof by Illustration”. Keep it in mind; we’re going to come back to it.

Tawa by Jorge Gonzalez

Let us now turn our attention to Tawa hallae, an interesting little theropod from the late Triassic. It’s notable for a few reasons:  among them are it’s bones, which are filled with air, a interesting but rather technical cladistic placement, and what it tells us about the dinosaur population of the Triassic era Petrified Forest. It’s also notable for being known from two nearly complete specimans and assorted scraps, which is rare for small Triassic theropods: for the most part, the bones are crushed and mangled by time and pressure. It was discovered a few years back, but due to the painstaking work involved in describing an animal scientifically, the paper has only just come out in science. And it is accompanied with some beautiful art by Jorge Gonzalez.

A Portrait (also by Jorge Gonzalez)

Nice, isn’t it? Mr. Gonzalez has picked out the scars on the snout, given it a slightly calculating expression reminiscent of a hawk. You can easily imagine the little fellow scuttling around the forest snapping up lizards, or stopping to preen its feathers.

However, there is a slight problem. Tawa isn’t known to have had feathers. None of its close relatives are known for it either. There’s no evidence for it. The images, gorgeous as they may be, are basically speculation.

There’s nothing wrong with speculation. It is, in fact, a huge basis of Paleontology. I don’t fault Mr. Gonzalez for dressing his beast in feathers, any more then I’d fault him for illustrating the probable appearance of an animal known from only a few bones. It’s what a good paleoartist does. And in all fairness, the word “feather” never once appears in the scientific paper. No one is claiming Tawa was fluffy.

Oh. Wait. Never Mind.

This is a rather nice example of the “Proof of Illustration.”  There’s no evidence for a feathered Tawa, either for or against. The fossil isn’t preserved with feathers. The paper never mentioned them.  But the illustration is there, and the majority of people will look at the image and assume the animal had feathers.

I find this interesting. In truth, the main reason most dinosaur myths hang on so long was because they are just too iconic to go away. Swamp dwelling brontosaurs, lurching tyrannosaurs, sluggish stegosaurs, gliding pterosaurs.  Those images, stamped into the public mind by Charles R. Knight and Zednek Burian, linger. Toys get made out of them, they are adapted for the silver screen, or swiped by inferior artists. They proliferate and achieve a kind of legitimacy. We’re so used to them we can’t imagine anything else.

The Dinosaur Renaissance had led us to many things, and one of its implicit promises was that all of the old and wrong images–iconic as they were–would be safely confined to the art galleries and history books. But the “Proof by Illustration” abides; it is a fundamental part of how people think. We may have gotten rid of some of those older ideas, but we’ve already begun shaping new icons, often with just as little evidence to support them.

Science marches on. Illustration, like imagination, often bounds far ahead–or lags far behind.