What is "lamellorthoceratidae"

Lamellorthoceratidae is a family of fossil nautiloids in the Orthocerida, defined by Curt Teichert in 1961. The lamellorthoceratids are placed in the superfamily Orthocerataceae in the Treatise on Invertebrate Paleontology (Walter Sweet, 1964).

Lamellorthoceratids are distinguished by cameral deposits consisting of simple or bifurcating epispetal, or rarely hyposeptal lamellae, set radially with respect to the siphuncle; often filling the entire posterior part of the shell. Lamellorthoceratid shells are straight or slightly endogastric with a slender, cylindrical subcentral orthochoanitic siphuncle, free or organic deposits.

The Lamellorthoceratidae are known from the Lower and Middle Devonian and possibly from the Lower Carboniferous, and is represented by three genera.