Davidhakania partingtonii

Davidhakania partingtonii Varol, 2025a

A species of Davidhakania is characterised by a symmetrical diagonal cross, with its acute angle aligned along the long axis of the discolith.

In honour of Dr M. Partington, Geological Adviser, Woodside, Perth, Australia, in recognition of his contributions to stratigraphy.

Length = 5.73 μm; Width = 3.38 μm; Height = 1.73 μm (all measured in XPL).

Optical Properties: Its optical properties are consistent with those of the genus Davidhakania. This species exhibits extinction lines with a typical extinction angle of approximately 74° on the distal side and displays length-fast (−) elongation.

Davidhakania partingtonii differs from Davidhakania saepes, another species with a symmetrical crossbar, by the orientation of its acute angle, which is aligned along the long axis of the discolith, whereas in Davidhakania saepes, it is aligned along the short axis.

Davidhakania partingtonii is distinguished from Davidhakania eosaepes and Davidhakania imbriei by possessing a symmetrical crossbar, whereas the latter species exhibit asymmetrical crossbars.

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