Maccoyoceras

Maccoyoceras is a genus of nautilids included in the family Trigonoceratidae from the Mississippian of North America (Michigan) and Europe.

Maccoyoceras Temporal range: Mississippian
Maccoyoceras concavum
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Nautiloidea
Order:	Nautilida
Family:	†Trigonoceratidae
Genus:	†Maccoyoceras Miller, Dunbar, & Condra, 1933

The shell of Maccoyocerasis evolute, volutions only slightly impressed, whorl section hexagonal. Venter flattened, flanks converging, umbilical shoulder prominent. Siphuncle slender, ventral of whorl center.