Michelinoceras

Michelinoceras
Temporal range: Ordovician to Triassic
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Orthocerida
Family: Michelinoceratidae
Genus: Michelinoceras
Foeste, 1932

Michelinoceras is the oldest known genus of the Michelinocerida, more commonly known as the Orthocerida, characterized by long, slender, nearly cylindrical orthocones with a circular cross section, long camerae, very long body chambers, and a central or near central tubular siphuncle free of organic deposits. Septal necks are straight; connecting rings cylindrical and thin. Cameral deposits are well developed. A radula has been found in one species, with seven teeth per row. It had ten arms, two of which formed longer tentacles.