Pontosphaera paynei

Pontosphaera paynei Varol, 2025a

This species exhibits a relatively high wall and a thin distal cover over the proximal plate. The proximal plate exhibits pores arranged in ten to twelve transverse or diagonal lines.

In honour of Dr S Payne, retired biostratigrapher/ micropaleontologist, Scotland, UK, in recognition of his contributions to biostratigraphy.

Length = 11.19; Width = 7.65 μm (both measured in PC).

Optical Properties: Pontosphaera paynei is characterised by a distinct difference in interference colours between the proximal plate with a thin distal cover and the wall, with the interference colours on the distal cover of the proximal plate being weaker compared to those on the wall in plan view. The extinction lines on the distal side are laevogyre and inclined at a typical angle of approximately 62° on the distal side. The species exhibits length-fast (−) elongation.

Pontosphaera paynei can be distinguished from Pontosphaera erythrathalassanica by its higher wall relative to the very thin distal cover, which makes it easier to separate the wall from the central area based on differences in interference colours. In contrast, Pontosphaera erythrathalassanica has a wall and distal cover of nearly equal height, making it more challenging to differentiate the wall from the central area.

Varol, O. 2025a. A practical guide to optical studies of calcareous nannofossils. Grzybowski Foundation Special Publication. 29: 1-222