Conusphaera maledicto

Conusphaera maledicto Varol & Bowman, 2019

Conusphaera mexicana minor Bown & Cooper, 1989a

From Latin maledicto, fence – referring to its fencelike appearance in the light microscope

Dimensions of holotype: Height = 2.52 μm; width (maximum) = 3.57 μm.

Small species (< 4.0 μm) of Conusphaera have a truncated conical shape, with the width commonly exceeding the height. The central core consists of four straight (uncurved) core segments that are visible in side view under the light microscope. In plan view, the species is strongly elliptical and individual segments are not discernible.

In side view under crossed polars at 0°, the lateral segments of the central core display first‑order white interference colours, whereas the very thin outer wall segments remain in constant extinction. In plan view, the central core likewise shows white interference colours.

Conusphaera mexicana minor Bown & Cooper, 1989a is a synonym of Conusphaera maledicto, but priority applies only within the same rank. As stated in ICN Art. 11.2, “A name has no priority outside the rank in which it is published (but see Art. 53.4).”

Varol, O. & Bowman, A.R. 2019. Taxonomic revision of selected Late Jurassic (Tithonian) calcareous nannofossils and the application of mobile mounting. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 291/1 (2019): 1–23

Bown, P. R. & Cooper, M. K. E. 1989a. Conical nannofossils in the Mesozoic. 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. 98-106.