''Litoceras'' is a trocholitid (Tarphycerida) genus that has been found in the Lower and Middle

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...

Newfoundland Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

. Whorls in ''Litoceras'' have a broadly rounded cross section with its width greater than its height. Litoceras somewhat resembles the tarphyceratid ''Pionoceras'' from the same time, except for the

siphuncle The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and ...

being dorsal and in the center.

Species

Species within the genera ''Litoceras'' include: * '' Litoceras calciferum'' (Billings, 1865) * '' Litoceras versutum'' (Billings, 1865) * '' Litoceras whiteavsi'' Hyatt, 1894

References

*Furnish, W.M and Glenister, Brian F (1964); Nautiloidea -Tarphycerida in the Treatise on Invertebrate Paleontology, Part L, Nautiloidea, Geological Society of America and Univ of Kansas press. {{Taxonbar, from=Q6648643 Prehistoric nautiloid genera Early Ordovician first appearances Middle Ordovician extinctions Paleozoic life of Newfoundland and Labrador Tarphycerida