''Karoceras'' is a genus of

oncocerid The Oncocerida comprise a diverse group of generally small nautiloid cephalopods known from the Middle Ordovician to the Mississippian (early Carboniferous; one possible member is known from the Early Permian), in which the connecting rings are ...

nautiloids that lived during the Silurian and possibly Early Devonian, type genus for the

Karoceratidae Karoceratidae is a family of nautiloids within the order Oncocerida The Oncocerida comprise a diverse group of generally small nautiloid cephalopods known from the Middle Ordovician to the Mississippian (early Carboniferous; one possible memb ...

. The shell is a compressed, exogastric cyrtocone, section sub ovoid. The siphuncle is ventral, near the outer, externally convex curvature. Septal necks flair outwardly, segments are inflated ventrally and are straight dorsally, a character of the family. ''Karoceras'' is the only member of the Karoceratidae that is actinosiphonate, a character produced by lamellae projecting radially inward toward the middle of the siphuncle from the connecting rings. This genus has been found in central Europe in the region of the Czech Republic and on Novaya Zemlya.

References

* Walter C. Sweet, 1964. Nautiloidea -Oncocerida, Treatise on Invertebrate Paleontology, Part K. Geological Society of America.
''Karoceras''
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Mar.5,2015 Prehistoric nautiloid genera Oncocerida {{paleo-nautiloidea-stub