3 genera are assigned to the class HELICOPLACOIDEA

OrderGenusFOPFOSLOPLOS
uncertainHelicoplacusCmAtda-uCmBoto-l
uncertainPolyplacusCmAtdaCmAtda
uncertainWestgardellaCmAtda-uCmAtda-u

Search Again
FOP = Period of first occurrence
FOS = Stage of first occurrence
LOP = Period of last occurrence
LOS = Stage of last occurrence

Stage abbreviations follow Sepkoski (2002).