Dual nomenclature in organic-walled dinoflagellate cysts II: Spiniferites elongatus and S. membranaceus, and their equivalent non-fossil species Gonyaulax ovum comb. nov. and G. lewisiae sp. nov.

Abstract

The cyst-defined extant Spiniferites elongatus Reid 1974 and Spiniferites membranaceus (Rossignol 1964) Sarjeant 1970 are environmentally significant fossil-species of the Quaternary, the former often dominating polar and subpolar assemblages. Following cyst incubation experiments and the establishment of cultures, these species were emended to incorporate information on their motile stages, and transferred to the non-fossil genus Gonyaulax Diesing 1866, as Gonyaulax elongata (Reid 1974) Ellegaard et al. 2003 and Gonyaulax membranacea (Rossignol 1964) Ellegaard et al. 2003. This unified approach to dinoflagellate nomenclature severs an important link with the fossil-genus Spiniferites Mantell 1850. We have applied dual nomenclature, as sanctioned by the International Code of Nomenclature for algae, fungi and plants, in returning these species to their previous assignments as Spiniferites elongatus and Spiniferites membranaceus, and we propose Gonyaulax ovum (Gaarder 1954) comb. nov., emend. and Gonyaulax lewisiae sp. nov., respectively, as their equivalent non-fossil species. A distinctive morphotype initially described as Rottnestia amphicavata var. amphicavata Dobell & Norris in Harland et al. 1980 is proposed as Spiniferites elongatus forma amphicavata stat. nov.