Pseudocypraea dolini, Pacaud, 2003

Pacaud, J. - M., 2003, First fossil records of the Recent Ovulid genus Pseudocypraea Schilder, 1927 (Mollusca, Gastropoda) with description of a new species, Geodiversitas 25 (3), pp. 451-462 : 456

Pseudocypraea dolini n. sp. ( Figs 3 C-E; 4A-C)

TYPE MATERIAL. — Holotype ( MNHN-DHT R63008).

ETYMOLOGY. — Named after Luc Dolin, in recognition of his help and his numerous contributions to Tertiary Cypraeid and Ovulid paleontology.

TYPE LOCALITY. — Le Quoniam near Haravilliers (Val d’Oise, France).

STRATIGRAPHIC HORIZON. — Early Bartonian (Marinesian, middle Eocene).

DIMENSIONS. — Height: 10.9 mm, maximal diameter: 6.6 mm.

IAGNOSIS. — A large fusiform Pseudocypraea , ornamented with strong spiral cords, the outerlip labial being short and strong.

DESCRIPTION

The shell is of a small size, fusiform, with an involuted protoconch. The dorsal area as well as the ventral area are deeply incised by a spiral sculpture (which the wear of the shell has not completely erased). The ventral sole is evenly convex, the neck, as pinched, forms an obtuse bottom. The aperture, quite broad, with subparallel sides, is evenly curved. The siphonal canal, cone-shaped, is deep and well defined. The terminal fold is lamellar, trimmed, long and straight, in an adaxial position. The auriform and concave fossula, which is reduced, slightly trimmed, and the convex columellar area, suggest the juvenile decoration. The angulation is slightly settled. The inner lip bears 18 strong, short teeth, which become thinner and more elongated adapically. The adapical edge, obscurely denticulated is thin, elongated and straight. The excurrent channel is deep, well defined and forms an adapical bridge, which is canaliculate and subaxially opening. The outer lip, crescent-shaped, slightly flattened by the callous development of the margin, bears 21 big short labral teeth, hardly more elongated in their abapical quarter. The outer lip shows spots of colour along the periphery.

DISCUSSION

A l t h o u g h t h i s d e s c r i p t i o n i s b a s e d o n a n unique specimen, Pseudocypraea dolini n. sp. differs from P. eratoformis n. comb., from P. adamsonii and P. exquisita ( Figs 4 D-F; 5) by numerous specific characters: tapering and non subglobose morphology, reduced fossula, adapical edge very thin, excurrent channel not curled and embayed, and indeed less numerous denticulation of the outer lip (21 shorter labral teeth in P. dolini n. sp., against an average of 26 in P. adamsonii , 20 in P. exquisita and 24 in P. eratoformis n. comb.). By the whole of its features, and in particular its subglobose general curve, excurrent channel curled and jagged, P. eratoformis n. comb. seems to be closer to the recent typical species. Under ultraviolet light ( Fig. 3C ) P. dolini n. sp. shows spots along the periphery of the outer lip that are typical of the genus Pseudocypraea ( Fig. 5E ).

Figures

FIG. 3. — A, B, Pseudocypraea eratoformis (Hoernes & Auinger, 1880) n. comb., Langhian (middle Miocene) of Lapugiu de Sus (Rumania), original pictures; C-E, Pseudocypraea dolini n. sp.; C, under ultraviolet light showing the trace of a colour pattern; D, E, ventral face and detail of the siphonal canal region. Scale bars: A, B, 3 mm; C-E, 5 mm.

FIG. 4. — A-C, Pseudocypraea dolini n. sp., Bartonian (Marinesian, middle Eocene) of Le Quoniam (Val d’Oise), holotype (MNHN- DHT R63008) (leg. J.-M. Pacaud); D-F, Pseudocypraea eratoformis (Hoernes & Auinger, 1880) n. comb., Langhian (middle Miocene) of Lapugiu de Sus (Rumania), holotype (NHMW 1999Z0077/0027). Scale bar: A-C, 5 mm; D-F, 3 mm.

FIG. 5. — A-C, Pseudocypraea adamsonii (Sowerby, 1832) of Huahine Island (Polynésie) (MNHN-DSE) (leg. L. Dolin); D-F, Pseudocypraea exquisita Petuch, 1979 of Bohol Island (Philippines) (MNHN-DSE) (leg. L. Dolin). Scale bar: 5 mm.