Paraseraphs praecedens, Caze & Merle & Pacaud & Saint Martin, 2010

Caze, Bruno, Merle, Didier, Pacaud, Jean-Michel & Saint Martin, Jean-Paul, 2010, First Systematic Study using the Variability of the Residual Colour Patterns: The Case of the Paleogene Seraphsidae (Mollusca, Gastropoda, Stromboidea), Geodiversitas 32 (3), pp. 417-477 : 460

Paraseraphs praecedens n. sp. ( Fig. 29E, F )

TYPE LOCALITY. — Abbecourt (Oise), France, Thanetian (Upper Paleocene), biozone NP9.

TYPE MATERIAL. — Holotype ( MNHN A05707 , leg. Pacaud)

ETYMOLOGY. — As the precursor of the Eocene Paraseraphs .

DESCRIPTION OF THE HOLOTYPE ( FIG. 29E, F ) Shell 19 mm in height and 7 mm in diameter, inflated and evolute with distinct suture. Spire short and blunt. Aperture long and narrow. Callus of the inner lip not preserved. Basal part of the columella and outer lip not preserved. No sculpture on the surface of the shell. No residual pattern observed under UV light (shell too poorly preserved).

COMPARISONS OF THE SHELLS

This species is easily distinguishable from the members of Seraphs by its evolute spire. Within Paraseraphs , although the shell of Paraseraphs praecedens n. sp. is incompletely preserved, it seems clearly stouter than the other species ( Fig. 29 D-F). Also, it is the smallest species of the genus.

DISCUSSION

From the Thanetian, Paraseraphs praecedens n. sp. is the oldest record of Paraseraphs for the world and the oldest record for the Seraphsidae in Europe. Previously, the oldest European occurrence of the Seraphsidae was Paraseraphs tetanus from the Ypresian (Cuisian, biozone NP 12) of the Paris Basin. Another species in this family is recorded in the?Late Paleocene-Early Eocene, Seraphs minus (Vincent, 1913) from Angola (Landana beds, Cabinda, West Africa). Jung (1974) regarded it as a nomen dubium, because the two syntypes “represent the immature stage of some species of Seraphs ”. However, although this species is only based on young specimens, it should be considered as one of the oldest records of the Seraphsidae , along with P. praecedens n. sp.

Figures

FIG. 29. — Paraseraphs Jung, 1974 shells in normal light: A-C, P. armoricus (Vasseur, 1882), MNHN A28788 (leg. Pacaud), Saffré (Bois-Gouët), Loire-Atlantique, France, Bartonian;A, ventral view; B, detailed view of the adapical part of the aperture; C, labral view; D, P. tetanus Jung, 1974, MNHN A29224 (ventral view) (Ferry coll.), Cuise-Lamotte, Oise, France, Ypresian (Cuisian), in comparison to P. armoricus and P. praecedens n. sp.; E, F, P. praecedens n. sp., holotype MNHN A05707 (leg. Pacaud), Abbecourt, Oise, France, Thanetian; E, ventral view; F, dorsal view. Scale bars: A, C, D-F, 10 mm; B, 5 mm. Photographs by C. Lemzaouda (MNHN).