Scacchia rodriguesensis Oliver & Holmes, 2004, n. sp.

• Main Authors: Oliver, P. Graham, Holmes, Anna
• Format: Other/Unknown Material
• Language: unknown
• Published: 2004
• Subjects: Biodiversity; Taxonomy; Animalia; Mollusca; Bivalvia; Galeommatida; Lasaeidae; Scacchia; Scacchia rodriguesensis; Baie du Nord; North Atlantic
• Online Access: https://zenodo.org/record/5462213; https://doi.org/10.5281/zenodo.5462213

Scacchia rodriguesensis n. sp. (figures 106–111) HOLOTYPE: one specimen from Baie du Nord, 2 m, mud, 19 ‡ 42.1 ’ S, 63 ‡ 22.5 ’ E. NMW.Z.2001.061.00033. PARATYPES: 7 rv, 4 lv and two shells, as holotype, NMW.Z.2001.061.00034. Measurements (mm, L 6 H). Holotype: 1.90 6 1.49. Paratypes: 2.16 6 1.81, 1.49 6 1.29, 1.51 6 1.18, 2.14 6 1.66, 2.40 6 1.93, 2.08 6 1.64, 1.96 6 1.54, 1.96 6 1.64, 1.98 6 1.53, 1.85 6 1.53, 2.17 6 1.63, 2.29 6 1.78, 2.36 6 1.83, 2.28 6 1.84, 2.72 6 2.07. Description. Shell to 3 mm in length. Thin. A little inflated. Equivalve. Inequilateral, beaks just behind the midline. Outline subovate, anterior slightly more expanded than posterior, umbos prominent. Dorsal margins set off from lateral margins by weak flexures (figure 107: af, pf); posterior margin sloping more steeply than anterior, rounded; ventral margin curved, anterior margin broadly curved. Sculpture smooth except for weak growth lines. Prodissoconchs I and II present, PdI 125 M m in diameter, weakly sculptured; PdII large, 320 M m in diameter, smooth with weak concentric lines. Hinge with small but distinct teeth; rv (figure 109) with a single projecting cardinal peg-like tooth, lateral teeth not developed but the anterior and posterior dorsal margins slightly flexed to form pseudo-teeth; lv (figure 110) with a pair of cardinal peg-like teeth, lateral areas not flexed. Internal ligament small, in a shallow oblique resilifer; external ligament thin on an indistinct nymph. Shell colour white, some with a pair of weak reddish radial rays or with a median tinted zone (figure 111). Derivation of name. Latin suffix ensis denoting place of belonging and Rodrigues, the known range of the species. Comparisons. The hinge structure suggests that this species belongs to the Erycinidae and because of the flexures in the right valve it is most reminiscent of the genus Scacchia. This genus has to date been confined in its use to Mediterranean and North Atlantic species (van Aartsen, 1996) but we could not find an alternative genus for the ...