Holcodiscidae
Holcodiscidae is an ammonite family placed in the superfamily Desmoceratoidea.
Description
Moderately involute with rounded, rectangular, or depressed whorl section; straight or sinuous, fine, dense ribs typically continuing over venter and may be periodically truncated by oblique, enlarged ribs, with or without umbilical, lateral and ventrolateral tubercles. Suture rather simple.Genera
AstieridiscusHolcodiscusJeanthieuloyitesParasaynoceras- ''Spitidiscus''