Halloceras is a gyroconic rutoceratid from the Lower Devonian of North America, with a subtriangular whorl section, narrow dorsum (on the inner side), divergent flanks, and broad, rounded venter (on the outer side), frills at various growth points, suture with shallow ventral and lateral lobes, and a small siphuncle near the venter.

Halloceras
Temporal range: 391.9–388.1 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Nautilida
Family: Rutoceratidae
Genus: Halloceras
Hyatt, 1884

Halloceras was named by Hyatt in 1884. The type us Halloceras undulatum.

References edit