Axinulus alleni ( Carrozza, 1981 )

Axinulus alleni ( Carrozza, 1981)

Fig. 7 a–c View FIGURE 7. a – c

Thyasira alleni Carrozza, 1981 (p. 224, pl. 1, figs. 1–3).

Thyasira ( Axinulus) alleni Carrozza, 1981 — Payne & Allen 1991 (p. 531, figs. 78–81). Thyasira alleni Carrozza, 1981 — Bonfitto et al. 1994 (p. 149, fig. 37); Repetto et al. 2005 (p. 308, mid left fig.).

Diagnostic characters. Obliquely subquadrangular shell; edentulous hinge; weak postero-dorsal radial depression; outer surface bearing growth lines only. Prodissoconch: shell type ST-2D; length about 120 µm; roundish D-shaped outline; convex profile; surface with irregular low wrinkles; rim-like shell lip barely separated from P-1; transition to the nepioconch well marked.

Occurrence. Box-corer sample BC72 (1 specimen). Height: 2.5 mm.

Distribution and habitat. Axinulus alleni ranges from NE Atlantic to West Africa ( Morocco, Angola and Cape basins) and to the Mediterranean, as far east as the North Aegean Sea, dwelling on medium-fine, organic muddy sand from about 150 to over 1500 m depth ( Carrozza 1981; Payne & Allen 1991; Salas 1996; Zenetos et al. 2005).

Fossil record. Upper Pleistocene of Sardinia ( Bonfitto et al. 1994).