Callianideidae Kossman, 1880

Poore, Gary C. B., 2015, Rediagnosis of Callianideidae and its genera (Crustacea: Decapoda: Axiidea), and description of a new species of Heardaxius Sakai, 2011, Zootaxa 3995 (1), pp. 229-240 : 231

Callianideidae Kossman, 1880

Callianideinae Kossmann, 1880: 80 .—De Man 1928: 20, 30.— Melin 1939: 4.— Balss 1957: 1582.—de Saint Laurent 1973: 515.— Sakai 1992: 10.

Callianideidae .— Gurney 1938: 343.—de Saint Laurent 1979: 1395.— Poore & Griffin 1979: 221.— Sakai 1987: 303.— Kensley & Heard 1991: 497 –498.— Sakai 1992: 9.— Poore 1994: 103.— Poore, 1997: 348.— Sakai, 2011: 197 –198.— Dworschak et al. 2012: 189.

Thomassiniinae de Saint Laurent, 1979: 1396.—de Saint Laurent & Le Loeuff 1979: 95.— Sakai 1992: 18.

Thomassiniidae .— Manning & Felder 1991: 765.— Poore 1994: 104.— Poore 1997: 398.— Sakai 2011: 524.— Dworschak et al. 2012: 189.

Diagnosis. Cephalothorax, rostrum, abdomen, telson unarmed, uropod sometimes with few small spines. Rostrum obsolete or small spine. Linea thalassinica lateral to eyestalks, ranging from very short to complete. Posterior margin of carapace evenly curved, without lobes interacting with pleomere 1. Thoracic sternite 7 broad, flattened at least posteriorly. Setal-rows present at least on anterolateral carapace, often on pereopodal propodi and some pleomeres. Eyestalks flattened, contiguous. Antenna with small articulating scaphocerite. Maxilla scaphognathite with single long seta on posterior lobe. Maxilliped 3 pediform. Pereopod 1 (cheliped) merus convex on lower margin. Pereopod 2 chelate. Pereopod 3 propodus ovate or subrectangular; pereopod 3 (sometimes 4 and/or 5) propodus with distal spiniform seta. Pleopods 2–5 similar, with elongate rami, each with elongate appendix interna, with or without marginal filaments. Uropod endopod ovate, exopod without dorsal plate (sometimes notched).

Remarks. The diagnosis here is short but sufficient to separate the family from others in Axiidea and is derived from those in Poore (1997) and Dworschak et al. (2012). While synapomorphies of Callianidea are easy to recognise, those unifying the remaining genera are more difficult to find. In Kensley & Heard’s (1991) cladistic analysis Crosniera , Mictaxius and Thomassinia were said to share a reduced maxilliped 3 exopod and a derived setal-row pattern. The maxilliped 3 exopod is not reduced in Crosniera and setal-row patterns vary considerably between all species. Poore (1994) grouped the three thomassiniid genera on the basis of a ‘linea thalassinica displaced dorsally, ocular lobe substituted by branchiostegal sclerite’ (in fact no different from Callianidea ), ‘middorsal tergite of pleomere 1 anteriorly depressed’ (in fact like many axiideans and contrasting with the domelike condition in Callianidea ), and ‘midanterior region of thoracic sternite 7 flattened and broadened (coxae secondarily separate)’ (several species are in fact not unlike Callianidea ). Other character states said to define the family vary between genera and are equally unconvincing. A molecular analysis involving just three taxa ( Robles et al. 2009) and others unpublished suggest that Thomassiniidae are polyphyletic or at best paraphyletic. Thomassiniidae is here synonymised with Callianideidae .