Argyrotheca cuneata ( Risso, 1826 )

Hansen, Jesper, 2024, Brachiopods of the Norwegian fauna northern North Atlantic and Arctic, with a focus on, Fauna norvegica 43, pp. 12-68 : 45-46

Argyrotheca cuneata ( Risso, 1826)

Figures 40 , 41

Terebratula cuneata Risso, 1826, p. 388 , pl. 12, fig. 179.

Terebratula soldaniana Risso, 1826, p. 389 , pl. 12, fig. 178.

Anomia pera Megerle von Mühlfeld, 1829, p. 205 , pl. 1, fig. 1a–b. Terebratula pera – Küster (1843), p. 30, pl. 2b, figs. 14–17.

Orthis pera – Philippi (1844), p. 69.

Argiope cuneata – Davidson (1852b), p. 373.

opening extending into dorsal valve. Deltidial plates rudimentary. Shell matrix endopunctate. Brachial loop in dorsal valve long, simple, bilobed and anteriorly attached to median septum. Triangular dorsal median septum reaching 4/5 valve length with a peak at 2/3 valve length. Ventral valve with a distinct median ridge extending to 4/5 valve length. Maximum shell length 3 mm.

Depth range: 2–645 m depth ( Logan 1979; Logan 2007). However, from the available data, it seems that this species is mostly found shallower than 60 m.

Temperature range: 12–20˚C ( Brand et al. 2003).

Salinity range: 37–38 ( Brand et al. 2003).

Geography: Southernmost Celtic Sea, the Mediterranean, Madeira, the Canary Islands and the Cape Verde Islands ( Logan 1979; Brunton & Curry 1979; Simon & Willems 1999; Logan et al. 2007).

Figures

Figure 40. Argyrotheca cuneata. a–e: dorsal, ventral, lateral, anterior and posterior views of specimen, 55 m (JH); f–j: dorsal, ventral, lateral, anterior and posterior views of specimen, 55 m (JH); k–l: dorsal and ventral interior views of empty shell, 80 m (JH); m: frontal view of dorsal valve interior of empty shell, 80 m (JH). All from the Saronic Gulf, Greece. Scalebar 1mm. Photos: Jesper Hansen.

Figure 41. Distribution of Argyrotheca cuneata.