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).