Recent proposals on nomenclature of dinoflagellates (Dinophyceae)

The recent proposals to conserve or reject dinoflagellate names are commented. The Nomenclatural Committee for Algae (NCA) recommended to conserve 
 Scrippsiella against 
 Heteraulacus and 
 Goniodoma (proposal #2382). The synonymy of 
 Peridinium acuminatum and 
 Glenodinium trochoideum is highly questionable, and one Steins illustration of 
 Goniodoma acuminatum as type will solve the doubts. An alternative genus and family name for the gonyaulacoid taxa formerly classified in 
 Goniodoma is not provided, and 
 Scrippsiella is a junior synonym of 
 Duboscquodinium. The NCA confirmed 
 Amphidoma acuminata as type species against 
 A. nucula (2577). Stein established 
 Amphidoma nucula as the representative species of the genus, and the poor-defined 
 A. acuminata is associated with higher nomenclatural instability because it is probably a 
 Centrodinium species. The NCA recommended 
 Heterocapsa steinii as type of 
 Heterocapsa (2607). That species name is a junior synonym of 
 Properidinium heterocapsum and 
 Peridinium monas. That taxon and allied species should be placed in 
 Cachonina because Stein proposed 
 Heterocapsa for three species of the Kryptoperidiniaceae. The proposal to conserve 
 Alexandrium against 
 Blepharocysta (2686) is based on that 
 Peridinium splendor-maris is a senior synonym of 
 Alexandrium balechii, currently classified in 
 Gessnerium. 
 Peridinium splendor-maris is a collective name that includes undefined organisms, and no description or illustration corresponded to 
 Alexandrium or 
 Gessnerium. The NCA reported that 
 Alexandrium catenella and 
 A. fundyensis are synonyms, without comments on 
 A. pacificum (2302). The consequence is that one of the five species of that group has not name. Naming taxa should follow the principle of priority and the article 7.3 of the International Code of Nomenclature for algae, fungi, and plants, and rejection or conservation of names should be exceptional. Based on a supposed nomenclatural stability, the NCA is creating arbitrariness and instability in naming dinoflagellate taxa based on questionable taxonomical interpretations.


62
Dinoflagellates are unicellular organisms with ~2500 correct species (Gómez 2012a). 63 About one half of the taxa are heterotrophic, but this percentage could be higher because 64 the descriptions of heterotrophic species receive less attention (Gómez 2012b). isosceles trapezoid with a flat antapex, and the epitheca was angled, convex, and with 153 cuspidate apex (Fig. 1A, ECdraw938). 154 Diesing ( Heteroaulax acuminatus. It is common to assign the type species to the first described 167 species in a publication that proposed several congeneric species and the generitype is not 168 specified. For example, Stein (1883) proposed the genus Podolampas for P. bipes and P. 169 palmipes, and Loeblich and Loeblich (1966) fixed P. bipes as type that is the first 170 illustrated species by Stein. In the case of Heteraulacus, Loeblich and Loeblich (1966)  and they did not report any illustration of their observations. Unequivocally Ehrenberg's 193 Peridinium acuminatum is not ovoid, and the details of Ehrenberg's illustrations suggest 194 that it is larger than Claparède and Lachmann's taxon.      Stein le nom de G. polyedricum (Pouchet). Cette innovation n'a pas été généralement 307 adoptée". However, Jørgensen's interpretation was partially followed in popular 308 monographs from northern Europe (Paulsen 1908, Schiller 1935 (Fig. 1A) when compared to the more common morphology in this taxon (Fig. 1B).

326
This pointed triangular apex is always missing in Glenodinium trochoideum (Fig. 1D    The apex was truncate, a feature that can find in some species of Protoperidinium (not in Stein (1883) illustrated as Goniodoma acuminatum (Fig. 1A-B). Even, if we accept the 585 questionable synonymy of Peridinium acuminatum (Fig. 1A) and Glenodinium 586 trochoideum (Fig. 1D), the designation of an illustration of Goniodoma acuminatum 587 sensu Stein 1883 (Fig. 1B) as type of the genus Goniodoma avoids the problems.   Amphidoma nucula (Fig. 4A), and it is easily recognizable in oceanic plankton samples 661 (Fig. 4B). There are no major problems in the identification of Amphidoma nucula, and 662 this allows to establish which species are circumscribed to Amphidoma. In contrast, Stein

663
(1883) provided only two illustrations of Amphidoma acuminata showing the same view, 664 and missing details on the tabulation (Fig. 4C). The only information about A. acuminata Wismar, near Kiel, Baltic Sea. He illustrated eleven individuals that suggest that the 692 species was abundant (ECdraw674) (Fig. 5A). He showed individuals divided into two 693 size classes and two views: One view showed cells with a more or less ellipsoidal contour.

694
As the sulcus is not illustrated, it is not possible to establish to which view corresponded ECdraw674 were expecting to find a cell with triangular shape.

711
From individuals collected at Kiel, Ehrenberg (1840) also described Peridinium 712 monas Ehrenberg (ECdraw951) (Fig. 6D). He illustrated numerous individuals with an 713 elongated bi-conical contour, with a wide and median cingulum. The apex was brunt and 714 the antapex sometimes pointed (Fig. 6D). The transversal section was circular. Ehrenberg 715 remarked in the short diagnosis that the species was 'sociable'. to other congeneric species of Peridinium monas (Fig. 9B)   Other congeneric species were already placed in Cachonina, and some species will need 965 to be transferred into that genus.