Diatom assemblages from an Eemian palaeolake in Northern Europe with morphological observations of rare Aulacoseira sp. resting spores

Abstract

An overview of the diatom flora of the last interglacial (Eemian) lacustrine gyttja deposit at Sokli, northeastern Finland is presented together with descriptions including photomicrographs of resting spores similar to the Aulacoseira islandica-skvortzowii group, not found in recent material from Europe. Comparisons are made with literature data on similar taxa. The morphology of the resting spores (e.g., the number of striae and areolae in 10 µm) links them to the A. islandica-skvortzowii group, but the lack of vegetative cells in the Sokli record makes the determination of true synonymy difficult. The presence of spores similar/related to the A. islandica-skvortzowii group in the Sokli Eemian palaeolake may reflect a more widespread distribution of this group in the past.

Keywords:

• Aulacoseira
• Aulacoseira islandica
• Aulacoseira skvortzowii
• resting spore
• morphology
• Pleistocene

Acknowledgements

This study was funded by the Swedish Nuclear Fuel and Waste Management Company (SKB) and the Bolin Centre for Climate Research at Stockholm University, Sweden. We thank the editor and two anonymous reviewers for valuable comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Swedish Nuclear Fuel and Waste Management Company (SKB) and the Bolin Centre for Climate Research, Stockholm University, Sweden.