The archeopyle in cretaceous palaeoperidinium eurypylum (manum and cookson) comb. nov., and similar dinoflagellates

Abstract

The Upper Cretaceous species originally named Scriniodinium eurypylum by Manum and Cookson (1964) is shown to possess a type of archeopyle and other features that require removal from Scriniodinium Klement. The species is redescribed and is transferred to Palaeoperidinium Deflandre. Other species with similar archeopyles are discussed and illustrated: Palaeoperidinium basilium (Drugg) Drugg and a closely similar, unnamed species from the Maastrichtian‐Danian (marine), Palaeoperidinium hansonianum (Traverse) Lentin and Williams from the Oligocene (freshwater), and Peridinium limbatum (Stokes) Lemmermann from the Holocene (freshwater). Contrasts with the archeopyle in another group of Cretaceous marine species, one of which has been misidentified as Scriniodinium eurypylum, are pointed out.