Shelbyoceras

{{Short description|Extinct genus of molluscs}}

{{Automatic taxobox

| taxon = Shelbyoceras

| authority = Ulrich & Foerste, 1931

| type_species = Shelbyoceras robustum

| type_species_authority = Ulrich & Foerste, 1936

| subdivision_ranks = Species

| subdivision = {{Species list

|S. bigpineyensis|Stinchcomb, 1986{{Cite journal

| last1 = Stinchcomb | first1 = B. L.

| title = New Monoplacophora (Mollusca) from Late Cambrian and Early Ordovician of Missouri

| journal = Journal of Paleontology

| volume = 60

| issue = 3

| pages = 606–626

| doi = 10.1017/s0022336000022149

| year = 1986

}}

|S. buttsi|Ulrich et al., 1943

|S. robustum|Ulrich & Foerste, 1936

|S. unguliforme|Ulrich et al., 1943

}}

}}

Shelbyoceras is a genus of Cambrian monoplacophora 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{{Cite journal | doi = 10.2307/1304159| jstor = 1304159 | pages = 45–49 | title = New Information on Late Cambrian Monoplacophora Hypseloconus and Shelbyoceras (Mollusca) | journal = Journal of Paleontology | volume = 54 | issue = 1 | publisher = Paleontological Society | year = 1980| author1 = Stinchcomb | first1 = B. L.}} (with whom it may be synonymous).{{Cite journal | last1 = Stinchcomb | first1 = B. L. | last2 = Echols | first2 = D. J. | title = Missouri Upper Cambrian Monoplacophora Previously Considered Cephalopods | journal = Journal of Paleontology | doi = 10.2307/1301748| volume = 40| jstor = 1301748 | issue = 3 | pages = 647–650 | year = 1966 }} The septa in this genus are either closely or irregularly spaced.