Definition. PLAkINIdAE ALWAyS WITH dIOdS, ANd WITH TRIOdS IN VARIAbLE AbUNdANcE OR AbSENT. CALTHROPS ARE ALWAyS AbSENT. MIcRORHAbdS, SPHERES ANd SPINEd dIOdS (qUASIAMPHIASTERS) MAy bE PRESENT IN SOME SPEcIES (AMENdEd fROM MURIcy 2011).
Type species: Plakortis simplex ScHULZE, 1880.