THE SCALE OF SCALES: WHY THE SHIFT IN DINOSAUR SCALE SIZE FROM THE NINETEENTH TO TWENTIETH CENTURY?

It was less than ten years after Buckland and Mantell described the first dinosaurs that attempts were made to recreate life-like images of these previously unknown creatures. George Scharff (1833), William Buckland (1836), and John Martin (1837) illustrated these initial renditions based on the rudimentary knowledge of the time. A particularly notable feature of these early dinosaur reconstructions is the size of the scales coating their bodies. Without preserved skin impressions, the interpretation of a dinosaur’s external appearances was left to the individual artist. Thus, many early dinosaur renditions were covered with large scales, in some cases measuring more than 30 centimeters across. At the time, reconstructions with large scales were likely done to show the saurian nature of these creatures and to ensure that the scales were visible when viewed from a distance.

The image of dinosaurs with large diameter scales is peppered throughout artwork, cartoons, and literature until the end of the 1800’s. The few descriptions of dinosaur skin identified from the 19^th century do not appear to sway this image, likely because many of those descriptions were in regional publications and unknown by non-scientists of the time. It is not until the early 20^th century that we see dinosaur scales shrink in artwork. The works of Charles R. Knight and Rudolph F. Zallinger provide examples of this reevaluation. But what brought about this change? Knight and Zallinger had associations with museums housing large dinosaur collections, including samples of newly discovered skin impressions. This, together with the two artists’ extensive studies into living creatures, likely played a part in the observed change in scale size.

Through the remainder of the 20^th and into the 21^st century, the discovery of skin impressions from a variety of dinosaur families has confirmed that, in general, dinosaur scales were not very large. In conjunction with finding evidence of feathers on various theropods and advances in technology providing insight into coloration, we now see increasingly realistic reconstructions of these creatures. Today’s paleoartists have access to information previously unavailable, leading to more accurate portrayals of dinosaurs in many types of popular culture media.