Terebratulina retusa ( Linnaeus, 1758 )

Bitner, Maria Aleksandra & Moissette, Pierre, 2003, Pliocene brachiopods from north-western Africa, Geodiversitas 25 (3), pp. 463-479 : 472

Terebratulina retusa ( Linnaeus, 1758) ( Fig. 6 A-F; Table 6)

Terebratulina retusa – Logan 1979: 37-43, text-fig. 8, pl. 3, figs 1-18. — Gaetani & Saccà 1985a: 15, 16, pl. 7, figs 5-10; pl. 9, figs 6-9. — Taddei Ruggiero 1994: 208, pl. 2, figs 1-3.

MATERIAL EXAMINED. — Six complete specimens, one ventral valve, and one dorsal valve from Algeria: LP- MNHN B.38659-B.38661 (see also Table 1).

OCCURRENCE. — This species is one of the best known brachiopods. In the fossil record it is known from the Neogene of Europe. Today it is widely distributed, occurring in the north-eastern North Atlantic and the Mediterranean Sea. The known depth range of T. retusa is from 3 to 1478 m.

REMARKS

This species is rare, occurring only in three outcrops in Algeria (see Table 1). Its presence in Algeria was mentioned by Fischer & Oehlert (1891) and Ficheur (1896d). Terebratulina retusa is a small species, variable in outline (see Fig. 6A, E ). The shell is covered with numerous, rather coarse, nodular, radial ribs, 24-48 in number. Small, triangular deltidial plates are disjunct. The investigated specimens are smaller than those hitherto described ( Brunton & Curry 1979; Logan 1979; Gaetani & Saccà 1985a). In the Pliocene this species is known from Italy ( Gaetani & Saccà 1985a; Gaetani 1986; Barrier et al. 1987; Benigni & Robba 1990; Taddei Ruggiero 1994) and Spain ( Pajaud 1977; Encinas 1992; Encinas & Martinell 1992). In modern seas it is widely distributed, from warm waters of the Mediterranean Sea ( Logan 1979) to cold waters of the North Atlantic ( Brunton & Curry 1979; Cooper 1981; Curry 1982; Logan 1993). It has a very wide depth range, but occurs most commonly between 100 and 500 m ( Curry 1982).

Figures

FIG. 6. — A-F, Terebratulina retusa (Linnaeus, 1758), Mustapha (Algiers), Algeria (LP-MNHN B.38659); A-D, ventral, dorsal, lateral and anterior views of complete specimen; E, F, dorsal views of complete specimens; F, SEM micrograph of juvenile specimen; G, H, Megathiris detruncata (Gmelin, 1790), SEM micrographs of ventral and dorsal views of complete specimen, Mustapha (Algiers), Algeria (LP-MNHN B.38665). Scale bars: 2 mm.