Spondylus gussonii Costa O. G., 1830

Fig. 6 a–c

Spondylus gussonii Costa O. G., 1830 (pp. 41–42).

Spondylus gussoni O.G. Costa—Jeffreys 1879 (p. 556); Spada et al. 1970 (p. 5, fig. 4). Spondylus gussonii Costa—Hidalgo 1917 (p. 655).

Spondylus gussonii Costa, 1829 — Robba 1968 (p. 491, pl. 38, fig. 1).

Spondylus (Corallospondylus) gussoni O.G. Costa, 1829 — Nordsieck 1969 (p. 56, pl. 9, fig. 35.02). Spondylus gussoni Costa—Di Geronimo & Li Gioi 1980 (pl. 4, figs. 5–6); Di Geronimo et al. 2005 (figs. 2.7, 3.3). Spondylus gussonii O.G. Costa, 1829 — Poppe & Goto 1993 (p. 73, pl. 11, fig. 3).

Spondylus (Corallospondylus) gussonii O.G. Costa, 1829 — Giannuzzi-Savelli et al. 2001 (p. 206, fig. 427). Spondylus gussonii Costa O . G., 1829— Repetto et al. 2005 (p. 302, mid right fig.); Mastrototaro et al. 2010 (fig. 5 i). Spondylus gussoni (O.G. Costa) — Rosso et al. 2010 (fig. 5 B).

Diagnostic characters. Oval to pyriform shell; expanded posterior side; denticulate inner margins; several radial rows of minute, short tubular spines; thin commarginal lamellae more clearly visible towards the ventral margin; right valve more irregularly sculptured, with coarse spiny processes in the attachment area. Prodissoconch: shell type ST-2B; P-2 length about 150 µm (P-1 ca. between 85–95 µm); P-2 roundish with faint concentric lines; convex profile; P-1 apparently weakly granular (partly eroded); P-1/P-2 boundary apparently poorly delimited; transition to the nepioconch well marked.

Remarks. Although dated 1829, the work of Costa was published in 1830 according to Fasulo (2013).

Occurrence. Box-corer samples BC05 (1 specimen), BC11 (5), BC41 (1), BC67 (1), BC70 (1), BC71 (2), BC72 (4). Maximum height: 19 mm.

Distribution and habitat. The species is typical of the Mediterranean, with records also from the Bay of Biscay, Portugal and the Azores; it lives attached to deep water coral branches from about 70 to 1850 m depth, being common around 600 m (Hidalgo 1917; Poppe & Goto 1993; Pons-Moyà & Pons 1999). It has been regarded as a preferential characteristic element of CB (deep-sea white corals) biocoenosis (Pérès & Picard 1964; Di Geronimo 1979[a]; Di Geronimo & Bellagamba 1985). In the Santa Maria di Leuca CWC biotope, it was found on hard substrates including coral branches (Mastrototaro et al. 2010), being common in framework-building coral and coral rubble thanatofacies (Rosso et al. 2010).

Fossil record. Upper Miocene (Tortonian) of Piedmont; Pliocene of southern France and Italy ; Pleistocene of Sardinia and southern Italy (Robba 1968; Di Geronimo 1979[a]; Di Geronimo & Li Gioi 1980; Di Geronimo & Bellagamba 1985; Barrier et al. 1987; Di Geronimo & La Perna 1997; Di Geronimo et al. 2005).