Description: This grasping appendage was listed as “arthropod appendage” on the inventory sheet. I will leave it as such—it is far different in morphology than the other three examples I have had before, all of which were probably attributed to Sidneyia and Anomalocarids. Based upon its size, it came from a relatively large animal, and was most likely used to seize prey. Whatever the precise taxonomic status, this is a most unusual and highly desirable specimen, made even more so by the fact that both the part and counterpart are present.

Reference: Briggs D.E.G., and R.A. Robison. 1984. Exceptionally preserved non trilobite arthropods and Anomalocaris from the Middle Cambrian of Utah. University of Kansas Paleontological Contributions, Paper 111:1-24.