Dinogymnium cretaceum subsp. undulacostatum

"subsp. undulacostatum" (Boltenhagen, 1977, p.68-69, pl.10, figs.1a-c,2a-b,3a-b,4a-b,5a-b) Lentin and Williams, 1981, p.85.  Combination not validly published: holotype not designated.  Originally Dinogymnium cretaceum var. undulacostatum (name not validly published), subsequently Dinogymnium cretaceum subsp. undulacostatum (combination not validly published).  Age: Turonian-Maastrichtian. Parent: Dinogymnium cretaceum