Rank Genus | Phylum Mollusca Family Bassleroceratidae | |
Lawrenceoceras is a genus of moderately curved, gently expanding bassleroceratids (Nautiloidia, Ellesmerocerida) from the Lower Ordovician of eastern North America. Septa dividing the chambers are close spaced; sutures straight, transverse; the siphuncle narrow, submarginal.
Lawrenceoceras is closely related to nautiloids such as Bassleroceras that gave rise to the Tarphycerida although it specifically may not be ancestral.
References
Lawrenceoceras Wikipedia(Text) CC BY-SA