Here are some photos of casts of skin impressions from the Triceratops “Lane” I took at the Black Hills Institute in June 2018. Lane is a mostly complete skeleton of T. horridus (formerly BHI 6273, now at the Houston Museum of Natural Science) with extensive skin preservation rivaling the famous hadrosaur mummies. These impressions remain unpublished to date and have only been presented in an SVP abstract (Larson et al. 2007).
The first photo above is of an upright display of skin from the sacrum and base of the tail. The next two photos show another cast of the same area lying on the ground, with a skin patch removed to show the underlying left ilium. These casts have the impressions in the original positions in which they were discovered. All of the scales are large, interlocking polygons, with a few have them having distinct nipple-like projections.
The two photos below are closeups of one of the “nipple” scales on the tail base. Some paleoartists have incorrectly depicted them as having large spines or bristles (see chart at bottom), but in reality they only have small nubbins. Additionally, they are distributed randomly and are not arranged in even rows. Hopefully these photos will clear up the misconceptions about their appearance.
- Larson, P., Larson, M., Ott, C., & Bakker, R. (2007). Skinning a Triceratops. Journal of Vertebrate Paleontology, 27(3), 104A.