Order Lituitida Starobogatov, 1983

Diagnosis

Cephalopods with longiconic orthoconic or weakly cyrtoconic conchs, with cyrtoconic or coiled apical part. Siphuncle tubular, narrow (up to 0.20 of whorl height). Septal necks straight (orthochoanitic), rarely cyrtochoanitic in apical conch parts, and long (usually 0.25–0.30 of chamber length but over 0.50 in some taxa). Connecting rings often disaggregated and covered with cameral deposits that extend to cover the septal neck and inner parts of the connecting ring. Cameral deposits often consist of longitudinal lamellae or sheets that longitudinally divide chambers. Initial chamber small (length = 0.4 mm), subspherical, without cicatrix (after Kröger et al. 2007, emended).