Evidence of Scale Diversity In The Late Jurassic Sauropod Diplodocus sp. From The Mother's Day Quarry, Montana.

The life appearance of dinosaurs is a hotly debated topic in the world of paleontology, especially when it comes to dinosaur integument. In the case of sauropods, however, the topic is harder to properly discuss due to the limited amount of fossilized skin impressions that have been discovered. So far sauropod integument fossils include titanosaur fetuses from Patagonia, diplodocid dorsal spines, foot impressions, and other isolated skin impressions found in association with sauropod fossil remains. Several prominent skin impressions have been found at the Mother's Day Quarry, located in the Bighorn Basin, Montana. These discoveries may bring up new important information about diplodocids, specifically Diplodocus sp. Here we describe a newly uncovered skin impression that gives evidence of scale diversity in the Diplodocus genus. The scales themselves represent tubercles and represent various shapes including: rectangular, oval, polygonal, and circular shaped scales. The tubercles themselves are small in size, the biggest of which only reach about 1cm in length. Considering how diverse the scale orientation is in such a small area of skin, it is possible that these impressions may represent a transition on the body from one region to another; perhaps from the abdomen to dorsal side, or abdomen to neck. Based on analysis of extant integument and scale orientation of crocodilians and other reptiles, it is possible to hypothesize on the location of the impressions relative to the body as well as the size and age of the individual. This work is co-authored by Jason C. Poole and Jason P. Schein from the Bighorn Basin Paleontological Institute.