Orbitolina pauletensis Schroeder 1962

Orbitolina pauletensis Schroeder 1962 View in CoL

? 1847 Orbitolites concava – Michelin, p. 28, pl. 7, fig. 9. Early Cenomanian, France.

T 1962 Orbitolina (Orbitolina) concava pauletensis – Schroeder, p. 189-191, pl. 20, fig. 1-2, 12. Early Cenomanian, France.

1964 Orbitolina (Orbitolina) concava pauletensis – Schroeder, p. 687, text-fig. 2. Early Cenomanian, France.

Diagnostic Features: An Orbitolina with a proloculus of max diameter c. 0.28mm. The embryonic apparatus diameter is c. 0.875mm. The supra-embryonic zone is highly subdivided. The sub-embryonic zone is thin, and weakly subdivided. Radial zone chamber passages are triangular at first, becoming rectangular in older chambers.

Remarks: Introduced as a new subspecies of Orbitolina concava by Schroeder (1962) based on type material from supposedly basal Cenomanian sandstones at St Paulet in the Gard region of southern France. At the time, Schroeder (1962) distinguished two other subspecies of Orbitolina concava : Orbitolina concava concava and Orbitolina concava qatarica . Orbitolina concava pauletensis was differentiated on the basis of a thin (0.04 – 0.05 mm) and poorly subdivided subembryonic zone. The embryonic apparatus appears to be around 0.875 mm in diameter (second largest to O. concava ), and the proloculus has a maximum diameter of 0.24 – 0.28 mm. The chamber passage shape is triangular becoming rectangular in adult chambers. Schroeder (1962) considered it the oldest member of a pauletensis – qatarica – concava lineage.

However, after 1962, Schroeder almost never mentioned the species again (it is completely ignored in his 1975 and 1985 reviews for example and only very briefly mentioned and illustrated by Schroeder (1964)).

Stratigraphic range: Earliest Cenomanian (confident but scarce records). Neumann & Schroeder (1981) mention it with a late Albian – early Cenomanian range, but without explanation. In practice, the species needs to be redescribed on the basis of type and topotype material, and if valid, its range reassessed.

Palaeogeographic distribution: In so much as the species is known, it appears to be endemic to the western Mediterranean (Western Neotethys).