Confirmation Bias With the Old Civil War Photograph

By the modern-pterosaur expert Jonathan Whitcomb

Skeptics have found apparent faults with the old photograph that we now call Ptp, the “Civil War pterodactyl photo.” Yet under closer examination, those supposed weaknesses evaporate. It seems that either confirmation bias or belief perseverance (or both) has played a role in how some persons have interpreted the photograph.


the Ptp photograph of an apparent Pteranodon

Six apparent Civil War soldiers standing over an apparent modern pterosaur


In the recent blog post “Modern Pterosaurs and Confirmation Bias,” I mentioned how I had been influenced by my original impression of those wings, but something else caused me to doubt Ptp many years ago, something I left out of that post.

It was that shoe of the soldier in front, the shoe that appeared to rest on the beak of the apparent Pteranodon. Something did not look right: how that shoe was on that beak. I feel sure I am not alone in that impression, but it requires a closer examination to come to understand what is happening when we look at that area of the photo.

My confirmation bias

When I considered the apparent absence of support from scientists, for Ptp, it seemed to confirm what I had already concluded from the feelings I had about the wings and about the shoe on the beak. I now recognize confirmation bias in my thinking. When my doubts were answered, in the first two months of 2017, it allowed me to tackle that question about the lack of support from scientists in general, why official recognition is taking so long.

Confirmation bias in the thinking of critics

One skeptic said, in an online forum posting, that there was no shadow under the “boot” of the man who appeared to be standing with a shoe on the beak. Look closer, however, and under magnification it becomes clear: There IS a shadow under that man’s shoe. The scientist Clifford Paiva (a physicist in California) has found more than that, for he has told us that the shadow under that shoe correlates with other shadows on the animal. In other words, that is a real animal (or animal model) with a real man with his shoe on its beak.

Yet this took a careful study by a scientist, before it was confirmed that the shadow of the shoe on the beak is a genuine shadow. We are very grateful to Clifford Paiva for all of his work with Ptp.


tree-branch prop under the beak of the apparent Pteranodon

Arrow points to the tree-branch prop; also look at the shadow under the shoe


Explanation for the strange appearance of the shoe

That does not mean that the strangeness of the appearance is pointless or without any foundation. There is an explanation, but it requires looking closer and thinking about the situation those men were in at the time the photo was taken.

That beak is propped up by an apparent tree branch (another evidence discovered by Paiva). What’s the significance? The photograph was taken before about the year 1870, when people needed to be kept motionless for many seconds. The photographer would use one or more props to help people keep still.

So how would you expect that man to hold his shoe on that beak? With very little weight, of course. What is the result? The man appears to have put only the left edge of the sole of his shoe onto that beak. It would have been out of place to fully rest much weight onto the beak, for that would easily have caused motion during the many seconds needed for photographic recording. Placing only a tiny bit of weight onto that beak was easier if the man had made contact with the beak with only the left edge of the bottom of his shoe. What would we expect from all of that? A shadow on the beak, under the shoe.

How does that relate to confirmation bias? The skeptic who said that there was no shadow under the shoe—that man probably had fallen into confirmation bias, having already concluded that the photo was a hoax. He saw something strange in the placement of that shoe on the beak and concluded there was no shadow cast by the shoe. In reality, it was exactly the opposite: There is a clear shadow there. Not only was that skeptic mistaken about the shadow but he was mistaken in assuming the photo, in general, was a hoax.

Why is it taking so long for scientists in general to recognize the significance of Ptp? The answer could take a whole book to explain. In general part of it is this: Too many persons have assumed, for too long, that it was a hoax, and it takes too much courage for many scientists to come forward and make a statement about this photograph. Thank God for the courage of the scientist Clifford Paiva.


copyright 2017 Jonathan Whitcomb


Modern Pterosaurs and Confirmation Bias

This skeptic has made many mistakes, and appears, to me, to have fallen into both confirmation bias and belief perseverance. As I cannot read his mind and he has not responded to my request for him to investigate the possibility of confirmation bias on his part, I’ll take the general case: Skeptics in general have been misguided by generations of indoctrination into 19th century dogmas, including the idea that all species of pterosaurs became extinct long ago.


The “Bible of Modern Pterosaurs” (nonfiction book)

Those with differing religious beliefs can work together in finding the truth. How we all need to work in harmony with those who seem, on the surface, to differ! How we need each other!





"Modern Pterosaurs" nonfiction book by Whitcomb

Nonfiction cryptozoology book Modern Pterosaurs by Jonathan David Whitcomb

The main point of this book is this: The photograph now called Ptp has significant points of evidence in its favor, and what were once thought to have been evidences of a hoax have now been seen as invalid or as having serious weaknesses. The great preponderance of evidence points to the interpretation that this is a 19th century photograph of a modern pterosaur. Scientific analysis fully supports this conclusion.


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About Jonathan Whitcomb

Jonathan David Whitcomb, of Murray, Utah, (formerly of Long Beach, California) has written four nonfiction cryptozoology books (nine total editions), each one about eyewitness reports of living pterosaurs.
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