- The Paleontological Society
The West Indian Top-shell, Cittarium pica (Linnaeus, 1758), is a very classic and common species of the Caribbean faunal province. Until now the only known fossil occurrence of Cittarium pica, and of the genus Cittarium, is from Pleistocene deposits restricted to the Caribbean province (Clench and Abbott, 1943). Despite the turbiniform shell, the monotypic genus Cittarium belongs to the family Trochidae and was assigned to the tribe Gibbilini Stoliczka, 1868 by Hickman and McLean (1990). This paper reports a new species of Cittarium and the only record outside the Caribbean province. More than twenty million years separate the single modern species of Cittarium and the new fossil species. All material collected is deposited in Muséum national d'Histoire Naturelle, Paris (MNHN).
STRATIGRAPHY AND PALEOBIOGEOGRAPHY SETTING
The five Cittarium specimens from the Upper Oligocene were collected during extensive field work on the Oligocene and Miocene faunas of Aquitaine (southwestern France). The outcrop where they were discovered is located near Dax and St-Paul-lès-Dax (Landes). In Aquitaine, Upper Oligocene deposits are accessible as outcrops only in the Adour basin situated in the southwestern part. These deposits were correlated with the calcareous nannofossil zones NP 24 and NP 25 (Cahuzac et al., 1995). They are transgressive and have been deposited after a major regression at the Rupelian (Stampian)/Chattian boundary. In the southern part of the Adour Basin, Kieken (1973) revealed a deeply incised submarine canyon, the “Paleocanyon of Saubrigues,” which is probably related to this major sea-level fall. The canyon was partially filled by Upper Oligocene deposits.
The Upper Oligocene deposits of the Adour basin contain a very rich mollusk fauna (about 1,600 species) which, partially, fills an important gap in our knowledge of the Cenozoic European fauna. This fauna is currently being described and comprises numerous new records of fossil genera (Lozouet, 2000). Classic …