Maelonoceras is a Late Ordovician - early Silurian oncocerid found in Ontario.
Description The shell is a faintly gibbous exogastric cyrtocone with subparallel dorsal and ventral profiles but adorally converging sides. The aperture visored, pear-shaped. The Siphuncle small, ventral.
Taxonomic relation Maelonoceras is nautiloid cephalopod included in the Oncoceratidae along with such genera as Oncoceras, Belotoceras, Digenuoceras, and Maimoceras.
References
Walter C. Sweet, 1964. Nautiloidea-Oncocerida. Treatise on Invertebrate Paleontology, Part K. Maelonoceras Fossilworks entry. Jack Sepkoski 2002. List of cephalopod genera