{{Short description|Extinct genus of cephalopods}}
{{Automatic taxobox | fossil_range = {{Fossil range | Upper Pennsylvanian | Cisuralian}} | image = Diorama of a Permian seafloor - coiled cephalopod, sponges, brachiopods (43887749560).jpg | image_caption = Reconstruction of ''C. texanum'' at Carnegie Museum of Natural History | taxon = Cooperoceras | authority = Miller, 1945 | type_species = {{extinct}}'''''Cooperoceras texanum''''' | type_species_authority = Miller, 1945 | subdivision_ranks = | subdivision = *''C. texanum'' <small>Miller, 1945</small> *''C. milleri'' <small>Tucker, 1977</small> }}
'''''Cooperoceras''''' is an extinct genus of nautilid cephalopods within the family Tainoceratidae. Its most characteristic trait is the presence of long paired hollow spines on its outer sides, which is one of the most extreme forms of shell ornamentation in nautiloids.<ref name=":0">{{Cite journal |last=Tucker |first=John K. |date=1977 |title=A new species of nautiloid (genus ''Cooperoceras'') from the Pennsylvanian of Illinois |url=https://www.jstor.org/stable/1303614 |journal=Journal of Paleontology |volume=51 |issue=2 |pages=363–366 |issn=0022-3360}}</ref> It lived from the Upper Carboniferous to the Lower Permian and its fossils have been found in North America and Europe.<ref name=":0" /><ref name=":1">{{Cite journal |last=Teichert |first=Curt |last2=Moore |first2=R. C. |last3=Zeller |first3=D. E. Nodine |last4=Furnish |first4=W. M. |last5=Stenzel |first5=H. B. |last6=Kummel |first6=Bernhard |last7=Glenister |first7=Brian F. |date=1964 |title=Part K, Mollusca 3, Complete Volume |url=https://journals.ku.edu/InvertebratePaleo/article/view/5262 |journal=Treatise on Invertebrate Paleontology |language=en |pages=413 |doi=10.17161/dt.v0i0.5262 |issn=2153-621X}}</ref>
== Description == The shell is evolute, with an open umbilicus and sinuous ribs at maturity. The flanks and venter are flattened. The flanks converge on the dorsum. The venter has a shallow median groove and carries long paired ventrolateral spines that are widely spaced and recurve posteriorly. The sutures form shallow rounded ventral and lateral lobes. The siphuncle is small, tubular, and subcentral.<ref name=":1" /><ref name=":2">{{Cite journal |last=Miller |first=A. K. |date=1945 |title=Permian Nautiloids from the Glass Mountains and the Sierra Diablo of West Texas |url=https://www.jstor.org/stable/1299091 |journal=Journal of Paleontology |volume=19 |issue=3 |pages=282–294 |issn=0022-3360}}</ref>
== Classification == ''Cooperoceras'' belongs to the Tainoceratidae, a diverse family of late Paleozoic to Triassic coiled nautilids.<ref name=":1" /> The genus may be descended from or share a common ancestor with ''Metacoceras'', another Carboniferous tainoceratid with shorter spines.<ref name=":0" /><ref name=":2" /> Only two species are currently recognized as belonging to the genus ''Cooperoceras, C. texanum'' and ''C. milleri''; an additional tentatively referred species, ''C''.? ''spinosum'', is likely only distantly related.<ref name=":0" />
== Ecology == The long ventrolateral spines may have acted as protection against predators.<ref name=":0" /> They show strong signs of wear in the last third of the mature whorl, suggesting that ''Cooperoceras'' was nektobenthic and moved close to the seafloor.<ref>{{Cite journal |last=Miller |first=A. K. |last2=Youngquist |first2=Walter |date=1949 |title=American Permian nautiloids |url=https://doi.org/10.1130/MEM41-p1 |journal=Geological Society of America Memoirs |volume=41 |pages=218}}</ref>
==References== {{Reflist}}{{Taxonbar|from=Q5167934}}
Category:Prehistoric nautiloid genera Category:Fossil taxa described in 1945 Category:Permian cephalopods Category:Lopingian animals
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