Mendicula ferruginosa ( Forbes, 1844 )

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 : 36-37

Mendicula ferruginosa ( Forbes, 1844)

Fig. 7 m–o

Kellia ferruginosa Forbes, 1844 (p. 192).

Axinus ferruginosus Forbes—Jeffreys 1881 (p. 703); Hidalgo 1917 (p. 160).

Axinus ferrugineus, Forbes—Locard 1886 (p. 466).

Cryptodon (Axinulus) ferruginosus (Forbes) — Verrill & Bush 1898 (p. 793, pl. 87, figs. 7–8).

Thyasira ferruginea Winckworth—Tebble 1966 (p. 80, text-fig. 35b; not text-fig. 35a = Axinulus croulinensis ; cf. Oliver et al. 2002, p. 50).

Axinulus ferruginosus ( Forbes, 1843) — Nordsieck 1969 (p. 80, pl. 13, fig. 48.11).

Thyasira (Axinulus) ferruginosa (Forbes) — Di Geronimo & Panetta 1973 (p. 106, pl. 2, fig. 14).

Axinulus ferruginosus (Forbes) — Caldara et al. 1981 (pl. 4, fig. 3).

Axinulus ferruginosus ( Forbes, 1844) — Thomsen & Vorren 1986 (pl. 6, fig. C).

Thyasira (Mendicula) ferruginea ( Locard, 1886) — Payne & Allen 1991 (p. 534, figs. 82–87); Giribet & Peñas 1997 (fig. 106).

Mendicula ferruginosa ( Forbes, 1844) — Oliver et al. 2002 (pp. 54, 68; pl. 3, fig. D; pls. 4, 22; text-fig. 6); Oliver et al., 2016 (online resource).

Leptaxinus ferruginosus ( Forbes, 1844) — Repetto et al. 2005 (p. 310, mid right fig.).

Diagnostic characters. Subquadrangular to suboval, longer than high shell; expanded anterior side; hinge with a blunt cardinal tubercle; outer surface with growth markings only; very shallow posterior radial depression; blunt sinuation of the postero-ventral margin. Prodissoconch: shell type ST-2D; length about 130 µm; weakly inequilateral ellipsoidal D-shaped outline; convex profile; surface with irregular radial wrinkles around the cicatrix; P-1 with a narrow swollen shell lip; transition to the nepioconch well marked, somewhat step-like.

Remarks. The species is sometimes referred to as M. ferruginea ( Locard, 1886) , an unjustified emendation of Forbes’ name (see Oliver et al. 2002, p. 68).

Occurrence. Box-corer sample BC72 (4); cores BC05 (1), BC67 (1), BC72 (1). Maximum length: 2 mm.

Distribution and habitat. Mendicula ferruginosa has a widespread distribution, including the northern Pacific, North and central Atlantic and the Mediterranean; it is a symbiont-lacking suspension feeder dwelling on mud and muddy sand from shallow shelf to abyssal depths ( Payne & Allen 1991; Buhl-Mortensen & Høisaeter 1993; Pons-Moyà & Pons 1999; Oliver et al. 2016). It was regarded as a typical element of VP (bathyal mud) biocoenosis ( Di Geronimo et al. 1982), also characterizing the Abra-Nucula biocoenosis in the bathyal of Taranto ( Di Geronimo & Panetta 1973).

Fossil record. Miocene of Calabria; Pliocene and Pleistocene of Norway, Great Britain and Italy ; Pleistocene of Denmark ( Monterosato 1872; Caldara et al. 1981; Di Geronimo & Bellagamba 1985; Di Geronimo & La Perna 1997; Petersen 2004; Tabanelli 2008).

Figures

FIGURE 7. a – c: Axinulus alleni (Carrozza, 1981); RV, sample BC 72, scale bars: 1 mm (a – b), 0.1 mm (c, prodissoconch); d – f: Thyasira flexuosa (Montagu, 1803); RV (e, f) and LV (d), sample BC 72, scale bars: 2 mm (d – e), 0.1 mm (f, prodissoconch); g – i: Genaxinus eumyarius (Sars M., 1870); RV (h, i) and LV (g), sample BC 72, scale bars: 1 mm (g – h), 0.1 mm (I, prodissoconch); j – l: Leptaxinus subovatus (Jeffreys, 1881); RV, sample BC 72, scale bars: 1 mm (j – k), 0.1 mm (l, prodissoconch); m – o: Mendicula ferruginosa (Forbes, 1844); RV, sample BC 72, scale bars: 1 mm (m – n), 0.1 mm (o, prodissoconch).