Lituitidae

Systematic Paleontology Class Cephalopoda Subclass Nautiloidea Order Tarphycerida Suborder Lituitina Family Lituitidae

The Lituitidae is a nautiloid family from the Ordovician, included in the Tarphycerida, represented by smooth or annulate shells that start off with a spiral portion followed by a long, orthoconic extension. Included are Lituites, the type, Ancistroceras, Angelinoceras, Bodoceras, Cyclolituites, Holmiceras, and Trilacinoceras.

Origin may be in the Estonioceratidae, based on the typically loose coiling of the initial portion. Similarities in the mature, orthoconic section, muscle attachment scars and thin siphuncle segments, to the Orthocerida are a matter of convergence. The long, generally straight, commonly expanding, section, aligned with the center of the coiled portion does warrant placing the Lituitidae in its own suborder, the Lituitina.

References W.M Furnish and Brian F. Glenister, 1964. Nautiloidea - Tarphycerida. Treatise on Invertebrate Paleontology. Park K. Entry for Lituitidae in fossilworks.org. http://fossilworks.org/bridge.pl?a=taxonInfo&taxon_no=128189