Eocithara rosenkrantzi, Merle & Pacaud, 2004

Merle, Didier & Pacaud, Jean-Michel, 2004, New species of Eocithara Fischer, 1883 (Mollusca, Gastropoda, Harpidae) from the Early Paleogene with phylogenetic analysis of the Harpidae, Geodiversitas 26 (1), pp. 61-87 : 70-72

Eocithara (s.s.) rosenkrantzi n. sp. ( Fig. 5D, E )

Eocithara sp. – Rosenkrantz 1970: 441.

Harpa sp. – Kollmann & Peel 1983: 87, fig. 196A (non B).

TYPE MATERIAL. — Holotype ( MGUH 15818 , copy MNHN R 63692).

TYPE LOCALITY. — Sonja Lens, East of TurritellaklØft, Nuussuaq Peninsula, West Greenland, Agatdal Formation, Thanetian.

ETYMOLOGY. — For Professor Alfred Rosenkrantz who collected the studied specimens.

MEASUREMENTS. — MGUH 15818 (copy MNHN R63692) (holotype): height 9.5 mm (the two first teleoconch whorls are broken), maximal width 6.2 mm.

DESCRIPTION OF THE HOLOTYPE

Shell 9.5 mm in height and 6.2 mm in width. Protoconch missing. The last three teleoconch whorls are preserved. Whorls conical, weakly convex. Spire 21% of total length. Suture simple, linear. Axial sculpture of lamellose, abaxially oriented major varices. Posterior part of major varices adapicaly projecting, moderately covering base of penultimate whorl. Ten major varices on first preserved whorl and 14 equally spaced varices on last whorl. No secondary varices present between major varices. Spiral sculpture not preserved or absent. Oblong aperture of 63% of total length, contracted in its abapical angle. Centre of columella straight, weakly curved in its anterior part. Columellar callosity small, well delineated in its labial part. Pseudoumbilicus very narrow, closed and delineated by columellar callosity. Umbilical ridge poorly expressed. Siphonal canal short, slightly curved dorsally. Outer lip thin, but thickened by last varice, orthocline, with parasigmoid outline.

COMPARISONS

This Paleocene species is the oldest known from the Atlantic Ocean. It has been already presented under the name Harpa sp. by Kollman & Peel (1983), who figured two specimens (fig. 196A, B). A closer inspection of the material reveals that the specimen in figure 196B cannot be referred to the Harpidae , but is a young Volutocorbis Dall, 1890 . Conversely, the specimen in figure 196A, chosen here as the holotype of E. (s.s.) rosenkrantzi n. sp., may be attribued to Eocithara ( Fig. 5F, G ). The holotype has rounded whorls, as in some E. (s.s.) mutica , but differs in its less developed spiral sculpture and, in particular, lacks a P1 spine.

Figures

FIG. 5. — A-C, Eocithara (s.s.) eucosmia n. sp., paratypes, MNHN R63434 et R63435 (Pacaud coll.), Bois-Gouët, Saffré, Loire- Atlantique, France, Bartonian; D-E, E. (s.s.) rosenkrantzi n. sp., holotype, MGUH 15818 (copy MNHN R63692), Sonja Lens, East of Turritellakløft, Nuussuaq Peninsula, West Greenland, Thanetian (Agatdal Formation); F, E. (s.s.) sp. 1, MNHN J05430 (Cossmann coll.), Coustouge, Aude, France, lower Ypresian; G-H, Eocithara (s.s.) sp. 2, MNHN R63432 and R63433 (Courtessolle-Griffe coll.), Les Capitelles, North of Aragon, Aude, France, lower Ypresian. Scale bars: A-E, 5 mm; F-H, 10 mm.