CORONARCTIDAE Renaud-Mornant, 1974

Fontoura, Paulo, Bartels, Paul J., Jørgensen, Aslak, Kristensen, Reinhardt Møbjerg & Hansen, Jesper Guldberg, 2017, A dichotomous key to the genera of the Marine Heterotardigrades (Tardigrada), Zootaxa 4294 (1), pp. 1-45 : 26

1.3 CORONARCTIDAE Renaud-Mornant, 1974 (emended by Hansen 2007)

Arthrotardigrades with cylindrical worm-like body. Trunk cuticle smooth, with folds, bearing three somatic cirri (B, C and E) or only one (E). Eleven cephalic sense organs present, including large flattened secondary clavae (occasionally occurring as indistinct areas). Three or four claws, connected to foot by membranes.

1.3.1 Coronarctus Renaud-Mornant, 1974 (emended by Hansen 2007; Figs 4 B, 10A, B)

Coronarctidae with unplated cylindrical body, with more or less pronounced cuticular folds. Three pairs of somatic cirri with accordion-like scapus. Conical head separated into two parts; anterior triangular part with median cirrus and flattened secondary clavae, posterior part narrower, bearing lateral cirri and primary clavae. Four claws on each leg displaying more or less important heterometry6. Buccal apparatus without stylet supports or placoids17. Digestive tract with poorly developed diverticula. Female with two seminal receptacles.

Type species: Coronarctus tenellus Renaud-Mornant, 1974

Selected literature for further information: Renaud-Mornant (1974, 1987b) and Romano III et al. (2011).

1.3.2 Trogloarctus Villora-Moreno, 1996 ( Figs 4 C, 10C)

Coronarctidae with elongated body with cuticular folds. Only one pair of somatic cirri (cirrus E) with accordion-like scapus. Eleven cephalic sense organs. Primary clava, small and globular, inserted separately from cirrus A. Secondary clavae flattened and not pronounced. Small cephalic cirri consisting of two parts: scapus and flagellum. External cirri equally distant from the internal cirri and the primary clavae. Spines on all legs. Three claws on each leg, very long on fourth leg. Buccal apparatus with bar-shaped placoids, but without stylet supports.

Type species Trogloarctus trionyches Villora-Moreno, 1996

Selected literature for further information: Villora-Moreno (1996).

Figures

FIGURE 4. Habitus drawings of marine heterotardigrades. A Archechiniscus, redrawn from Pollock (1976). B Coronarctus, redrawn from Renaud-Mornant (1987 b). C Trogloarctus, redrawn from Villora-Morena (1996). D Clavarctus, redrawn from Renaud-Mornant (1983). E Euclavarctus, redrawn from Renaud-Mornant (1975 a). F Exoclavarctus, redrawn from Renaud- Mornant (1983). G Moebjergarctus, redrawn from Bussau (1992). H Parmursa, redrawn from Hansen (2007). I Proclavarctus, redrawn from Renaud-Mornant (1983).