Within the middle Cambrian aged shales of Utah you can find an odd cystoid called Gogia spiralis. It is a primitive echinoderm that is most recognizable by the way the arms twist like a helix or spiral and has a short stump below the main body that served as it's attachment point to the substrate. The body is covered with irregularly sized and spaced plates that don't seem to form a pattern to me. Below are three different specimens, these first two from the Wheeler Shale
I'm not sure if this specimen is from the Wheeler shale or not. The rock is a different type that is harder and colored differently. Possibly the Marjum formation? I bought it at the Rutgers University annual surplus sale and the label only states "Cambrian, Utah" for the locality info.