A review of the nomenclature of Gyrogona and Gyrogonites (Fossil Algae: Charophyceae)

Abstract

AbstractAnalysis of the nomenclature of the fossil genus Gyrogonites Lam. (Algae: Charophyceae) shows that the name was first treated by Lamarck (1801) as an incompletely known fossil mollusk from France. The species was given the name Gyrogonites medicaginulus because of its resemblance to the fruit of Medicago sativa (lucern). The gyrogonites were shown to be fossilized charophycean reproductive structures by Leman in 1812, now understood as calcified female gametangia preserved after the escape or the decomposition of protoplasmic material. Differences in the starting date of zoological nomenclature (1 Jannuary 1758) and that of plant fossils (1 January 1820) are resolved by Art. 45.1 of the botanical code, by which Gyrogonites is acceptable as a validly published pre‐1820 fossil charophycean name even though it was originally treated as a fossil animal. Gyrogona Lam. (1805) is a superfluous renaming of Gyrogonites (still considered at that time as a zoological name for a mollusk) and therefore should be rejected under the botanical and zoological codes. The inclusion of the type of Gyrogonites in the later established fossil higher‐plant genus Bechera Sternb. (1825), a repository genus for vegetative verticillate axes and reproductive organs, renders the latter genus name as nomenclaturally superfluous and illegitimate. Six fossil species of Gyrogonites are validated for the first time, 19 species and related 2 subspecies of Gyrogona are formally recombined into Gyrogonites. Two names, G. lemanii and G. oehlertii, are neotypified, and a lectotype is designated for G. wrightii. Precise dates of publication of the taxonomic works on gyrogonites of Bowdich, Brongniart, Fleming, Lamarck and Parkinson, supplementing records of Taxonomic literature II, are given for the first time.