Whitfieldoceras

Systematic Paleontology Order: Orthocerida Family: Clinoceratidae Genus: Whitfileldoceras

Whitfieldoceras is an orthocerid nautiloid included in the Clinoceratidae from the middle and upper Ordovician of North America. Shells are apically curved fusiform orthocones that expand gradually to the posterior end of the body chamber, then contract to the aperture. Sutures are straight and transverse, septa shallow. Siphuncles are central or slightly ventral, cyrtochoanitic, segments expanded in the chambers, and apparently empty.

Whitfieldoceras from across North America differs from Whiteavesites, apparently restricted to Manitoba, in that its sutures are straight and transverse rather than sinuously curved and from European Clinoceras in that the body chambers simply contract from the base to the aperture rather than contracting at some point, then expanding to the aperture.

References: Walter C. Sweet, 1964. Nautiloidea - Orthocerida Treatise on Invertebrate Paleontology, Part K.