Akanthophoreidae Sieg 1986

Family Akanthophoreidae Sieg, 1986 restricted (new rank)

Diagnosis. Antennule four-articled. Mandibular molar-process chitinized, tapering to thin, denticulate tip. Cutting edge of fixed finger of chela with blade-like apophysis bearing three or four denticulations; merus and carpus of all pereopods with compound spines rather than setae; merus and carpus of pereopods 2 and 3 not compact, carpus longer than merus, propodus not ventrally convex; dactylus elongate, angular in cross-section with finely setulose edges; unguis not fused. Pleopods present. Uropod endopod two-segmented, elongate, exopod two-segmented, shorter than proximal endopod segment. Marsupium formed from four pairs of oostegites.

Males of swimming-type, with well-developed pleon as long a shortened peraeon, and with reduced/atrophied mouthparts; uropod endopod commonly three-segmented.

Remarks. A number of recent cladistic analyses (Larsen & Wilson 2002; Bird & Larsen 2009; Błażewicz-Paszkowycz & Poore 2008) have failed to resolve certain genera into a structure of larger families, and as a result have left them incertae sedis at the immediate suprageneric taxon level, even when they have originally been assigned to families from original descriptions, or from traditional taxonomic revisions or phylogenetic analyses (e.g. Sieg 1983; Guţu & Sieg 1999). Larsen & Wilson (2002) were the only authors to include Akanthophoreus Sieg, 1986, which they assigned as incertae sedis; but as it was designated as the type genus of the subfamily Akanthophoreinae by Sieg (1986a) this genus does have an immediate suprageneric attribution, and Sieg’s subfamily is herein raised to family rank to accommodate this genus at least, and probably also Paraleptognathia Kudinova-Pasternak, 1981 and Chauliopleona Dojiri & Sieg, 1997, until the vexed and apparently enigmatic phylogeny within the Paratanaoida is properly resolved.

The diagnosis has been restricted from that of Sieg (1986a) to exclude genera now moved to Tanaellidae Larsen & Wilson, 2002 and Colletteidae Larsen & Wilson, 2002. The type genus, as assigned by Sieg (ibid.) is Akanthophoreus.