Anthalona, Van Damme, Sinev & Dumont, 2011

DAMME, KAY VAN, SINEV, ARTEM YU & DUMONT, HENRI J., 2011, Separation of Anthalona gen. n. from Alona Baird, 1843 (Branchiopoda: Cladocera: Anomopoda): morphology and evolution of scraping stenothermic alonines, Zootaxa 2875 (1), pp. 1-64 : 57

Anthalona gen. n., not Alona Baird, 1843 or Biapertura Smirnov, 1971

Anthalona gen. n. has no unique characters (autapomorphies) but a unique set of characters (synapomorphies) within the Aloninae . We listed these features earlier ( Van Damme & Dumont 2008b) and we repeat them here. We recognize Anthalona gen. n. by (1) Two connected main pores and lateral pores with 8–shaped structures below, (2) A short, S-shaped postabdomen with short basal spine (1–1.5 times base of claw), (3) Lateral fascicles with long distal spines, (4) Proximal denticle(s) on the labral keel (not A. brandorffi or A. simplex n. sp.), (5) Modified IDL armature on first limb and modified third and sixth scrapers on second limb (not A. simplex n. sp.), (6) Body with expanded posteroventral portion (not A. mediterranea or A. simplex n. sp.).

Separation of A. verrucosa Sars, 1901 and relatives in a genus in its own right, follows revision of other Alona species complexes. The morphological divergence is relatively clear in this case. A. quadrangularis (O.F. Müller, 1776) , type species of Alona Baird, 1843 , may be a separate lineage of the Hexalona -branch ( Van Damme & Dumont 2008a,b). Anthalona gen. n. is of an entirely different lineage in the Aloninae , sharing none of the features of the Hexalona -branch (e.g., Anthalona has no ventral setules on labrum, postabdomen is much shorter, its marginal teeth are unmerged). Also different from the main line of “true” Alona , can be seen in the fact that Anthalona gen. n. limbs have several reductions (e.g. two setae in IDL, six setae on exIII, no gnV, no P6, etc.).

The morphological characters indicate a divergence between Anthalona gen. n. and true Alona Baird, 1843 . Furthermore, differences between Anthalona species reveal a distinct evolution within the genus. Anthalona gen. n. is more similar to Coronatella Dybowski & Grochowski, 1894 and the Alona monacantha complex (likely also part of Coronatella ) and shares resemblance with Karualona Dumont & Silva-Briano, 2000 ( Van Damme & Dumont 2008b). It is possible that these two-pored animals form a separate small lineage. Postabdomen is of a similar, short type, both have two main head pores and limbs are similar but more reduced in Anthalona gen. n. Karualona and Anthalona are clearly different (for list of characters, see Van Damme & Dumont 2008b). We support the suggestion of Kotov that Karualona may be a sister group of Anthalona gen. n. (Kotov 2004, as Alona verrucosagroup ). Arguments for not placing A. verrucosa and related species in Coronatella are subtler and are discussed in the next section.