Taxonomic revision of the recent and holocene representatives of the Family Darwinulidae (Crustacea, Ostracoda), with a description of three new genera

The Darwinulidae, the only surviving family of the superfamily Darwinuloidea, are revised and 28 extant species are retained. Twenty-six species (two of which as yet formally undescribed) are allocated to five genera, three of which are here described as new; two species have an uncertain position within the family because of their insufficient original description and are listed here as species inquirendae. The new genera are characterised on combinations of soft part and valve characters, but the chaetotaxy of the limbs seems most conservative and most suitable for the identification of genera. Darwinula s.s. and Microdarwinula are, with regard to Recent species, monospecific. Alicenula nov. gen. is erected to comprise the three species of the former serricaudata-group. Vestalenula nov. gen. comprises the eight species of the pagliolii-boteai group, as well as Darwinula danielopoli, which, together with two undescribed species from Cuba and Tunisia, is placed in a special group within this new genus. Penthesilenula nov. gen. comprises two species-groups, with ten species in total: seven species in the incae-group, exclusively occurring in the southern Hemisphere, and three species in the africana-group. The latter group also contains P. malayica and P. brasiliensis, which occur on at least three continents; the latter species appears to have a higher incidence of morphological variability than the other extant darwinulids. The species-groups in the latter two genera are here used for convenience; no taxonomic value should at present be attached to them. Problems related to clonal taxonomy in general are briefly discussed. It is demonstrated that a systematic revision of an ancient asexual lineage can lead to a taxonomy which at the same time reflects natural phylogeny and is workable, i.e. is based on recognisable taxa.