Shelbyoceras is a genus of Cambrianmonoplacophora which was one of the genera mistaken for a cephalopod, since the characteristics differentiating monoplacophora from cephalopods are few. Shelbyoceras was reclassified based on a depressed groove that forms a band around the shell, which is similar to a feature seen in Hypseloconus[2] (with whom it may be synonymous).[3] The septa in this genus are either closely or irregularly spaced.[2]
References
^Stinchcomb, B. L. (1986). "New Monoplacophora (Mollusca) from Late Cambrian and Early Ordovician of Missouri". Journal of Paleontology. 60 (3): 606–626. doi:10.1017/s0022336000022149.
^ abStinchcomb, B. L. (1980). "New Information on Late Cambrian Monoplacophora Hypseloconus and Shelbyoceras (Mollusca)". Journal of Paleontology. 54 (1). Paleontological Society: 45–49. doi:10.2307/1304159. JSTOR1304159.
^Stinchcomb, B. L.; Echols, D. J. (1966). "Missouri Upper Cambrian Monoplacophora Previously Considered Cephalopods". Journal of Paleontology. 40 (3): 647–650. doi:10.2307/1301748. JSTOR1301748.