Ankumia van Veen, 1932 retained and not replaced by the junior taxon Platella Coryell & Fields, 1937 (Ostracoda, Platycopina, Cytherelloidea)

Abstract. Recently, the monotypic ostracod genus Ankumia van Veen, 1932 was abandoned as nomen dubium by Jones (2003, p. 85) in favour of Platella Coryell & Fields, 1937 and a new combination was proposed for the type species of Ankumia, i.e. Platella bosqueti (van Veen, 1932). However, Ankumia bosqueti from the Maastrichtian of The Netherlands was introduced as an available taxon and, as documented by Jones (2003), the specific name is valid for recognizing the species in which ‘pathological individuals with retained moults’ occur. Therefore, there is no reason to treat Ankumia as nomen dubium. Yet, although there is no doubt about the cytherellid relationship of the species, two taxonomical questions still remain.

(1) Do pathological individuals of cytherellids justify specific and/or generic ranking? Certainly they do not, and demonstration of a corresponding ‘normal’ species (including ‘pathological individuals’) among the associated cytherellids is wanting. On the other hand, if these pathological individuals can be proven as representing a discrete pathological genus, Ankumia remains as a valid genus to characterize the available species name bosqueti.

(2) Why should Ankumia be abandoned in favour of Platella? When van den Bold (1967, pp. 306, 308) compared Coryell & Fields’ original Gatún ostracod fauna with his own collection from the Neogene Gatún Formation in the Panama Canal Zone, he recognized the type species, Platella gatunensis, as a small-sized cytherellid moult. Over the years about a dozen small- and normal-sized cytherellid species from all over the world have been assigned to Platella, ignoring the questionable taxonomic . . .