Cretarhabdus barremianus

Cretarhabdus barremianus Black, 1971a

The placolith exhibits first-order, slightly greyish-white interference colours. The pelaga of Cretarhabdus barremianus shows inclined extinction and length-fast (-) elongation in plan view under crossed polars.

Species of Cretarhabdus are constructed of cretarhabdid pelaga surrounding a large central area spanned by an axial cross that supports a distal process. The inter-cross area is occupied by lateral bars that delimit pores arranged in two or more complete concentric cycles. The number of pores in the outer cycle is typically 12, but rarely 11 or 13, a feature characteristic of Cretarhabdus barremianus.

Black, M. 1971a. Coccoliths of the Speeton Clay and Sutterby Marl. Proceedings of the Yorkshire Geological Society 38: 381-424.

Crux, J. A. 1989. Biostratigraphy and palaeogeographical applications of Lower Cretaceous nannofossils from north-western Europe. In: Crux, J. A. & van Heck, S. E. (Eds) Nannofossils and their applications: Proceedings of the 2nd INA Conference, London 1987. British Micropalaeontological Society Publication Series. 143-211.