Ledella marisnostri La Perna 2004, n. sp.

Ledella marisnostri n. sp. (figure 4 a–e) Type material. Holotype (right valve, MZB 40663) and five paratypes (loose valves, author’s collection). Type locality. Cruise ‘ Interreg Italia-Albania’, southern Adriatic, st. 55, 40 ° 00 ∞ 59 ◊ N, 19 ° 08 ∞ 55 ◊ E, 976 m. Material examined. Only the type...

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Bibliographic Details
Main Author: La Perna, R.
Format: Other/Unknown Material
Language:unknown
Published: Zenodo 2004
Subjects:
Online Access:https://doi.org/10.5281/zenodo.4653812
http://treatment.plazi.org/id/03822624D810AE7494DCFB066FBDF991
Description
Summary:Ledella marisnostri n. sp. (figure 4 a–e) Type material. Holotype (right valve, MZB 40663) and five paratypes (loose valves, author’s collection). Type locality. Cruise ‘ Interreg Italia-Albania’, southern Adriatic, st. 55, 40 ° 00 ∞ 59 ◊ N, 19 ° 08 ∞ 55 ◊ E, 976 m. Material examined. Only the type material. Description. Shell small, ovate, moderately convex and elongated, inequilateral, thin-walled. Umbo rather large, weakly projecting from shell outline. Antero-dorsal margin sloping, slightly convex, smoothly curving into a well-rounded anterior margin. Postero-dorsal margin sloping, longer than antero-dorsal one, slightly convex, curving into a moderately developed blunt rostrum at shell height midline. Ventral margin wide, strongly convex, evenly rounded except for an obscure posterior sinuosity marking out rostrum. Hinge plate moderately thick, making a 130 ° angle, with rows of similar length. Dentition taxodont, with chevron-shaped teeth, numbering seven anteriorly and six posteriorly in holotype. Ligamental pit rather deep, somewhat triangular. Muscle scars and pallial line indistinct. Surface with fine growth striae, some of them more incised. Periostracum thin, shiny, yellowish. Prodissoconch elliptic, ca 250 µ m long. Holotype 2.08 mm in length, 1.53 mm in height, 0.50 in breadth. Paratypes 1.65–2.27 mm in length. Etymology. After Mare nostrum , Latin name for the Mediterranean Sea. Distribution. Only known from the type locality. Remarks. The sole species of Ledella so far known from the Mediterranean is L. messanensis , with a wide latitudinal distribution through the European Atlantic (Warén, 1978, 1989; Allen and Hannah, 1989; Salas, 1996). However, it differs markedly from the present species by being bigger (up to ca 5 mm), much more solid, and with a longer and sharper rostrum. Also, the juveniles of L. messanensis are somewhat pointed posteriorly and thick-shelled. A North Atlantic species, Ledella confinis (Smith, 1885), revised by Warén (1978), may be somewhat reminiscent of L. marisnostri ...