Yoldiella nana ( Sars M., 1865 )

Negri, Mauro Pietro & Corselli, Cesare, 2016, Bathyal Mollusca from the cold-water coral biotope of Santa Maria di Leuca (Apulian margin, southern Italy), Zootaxa 4186 (1), pp. 1-97 : 18

Yoldiella nana ( Sars M., 1865)

Fig. 3 a–c

Yoldia nana Sars M., 1865 (p. 99).

Yoldiella fraterna Verrill & Bush, 1898 (p. 867, pl. 80, fig. 5; pl. 82, fig. 8).

Yoldiella nana ( M. Sars, 1865) — Giribet & Peñas 1997 (p. 82, fig. 87); Giannuzzi-Savelli et al. 2001 (p. 56, figs. 52–54); La Perna 2003 (p. 26, pl. 3, figs. 4–5); Oliver et al. 2016 (online resource).

Yoldiella nana ( Sars M., 1865) — Repetto et al. 2005 (p. 285, top right fig).

Diagnostic characters. Suboval outline; faintly pointed anterior side; hinge with two thin alignments of very small teeth; shiny outer surface. Prodissoconch: shell type ST-1A; P-1: length about 130 µm; ellipsoidal outline; low convex profile; surface appears smooth; transition to the nepioconch not well preserved.

Remarks. Yoldiella fraterna Verrill & Bush, 1898 , is currently regarded as a junior synonym of the present taxon (CLEMAM 2016).

Occurrence. Box-corer sample BC72 (5 specimens); core BC05 (4). Maximum length: 2 mm.

Distribution and habitat. Yoldiella nana is distributed from Canadian Arctic and Siberia to both sides of the northern Atlantic (also entering Norway fjords) and the western Mediterranean; it has been found from about 100 to 1200 m depth ( Buhl-Mortensen & Høisaeter 1993; Pons-Moyà & Pons 1999; Oliver et al. 2016).

Fossil record. Upper Pliocene of Greenland ( Funder et al. 2001); Pleistocene of the Strait of Bering and the Mediterranean ( Hopkins et al. 1972; La Perna 2003).

Figures

FIGURE 3. a – c: Yoldiella nana (Sars M., 1865); RV (b, c) and LV (a), sample BC 72, scale bars: 0.5 mm (a – b), 0.1 mm (c, prodissoconch); d – f: Yoldiella philippiana (Nyst, 1844); RV, sample BC 72, scale bars: 1 mm (d – e), 0.1 mm (f, prodissoconch); g – i: Yoldiella striolata (Brugnone, 1876); RV, sample BC 72, scale bars: 1 mm (g – h), 0.1 mm (i, prodissoconch); j – m: Asperarca nodulosa (Müller, 1776); LV, sample BC 11, scale bars: 5 mm (j – k), 1 mm (l, juvenile), 0.1 mm (m, prodissoconch).