Occurrence of two Krsticiella species in Beringia suggests this genus is a Cenozoic relict

Abstract

The genus Krsticiella Levkov was previously known only from the basins of Lakes Ohrid and Prespa, and from Lake Baikal. Examination of type materials of diatoms originally described by Niels Foged from the North Slope of Alaska revealed that Navicula lenis Foged and N. meadeensis Foged belong to Krsticiella, to which they are formally transferred here. One of these species, K. lenis, is also found in thermokarst tundra lakes of the Kolyma Lowland in Northeastern Siberia. Several illustrations in previously published floras of Pliocene and Pleistocene diatoms of Eurasia indicate wider past distributions of Krsticiella species. The current restriction of this genus to non-glaciated regions of the Arctic and large ancient lakes in temperate zone indicates that it is a Cenozoic relict.

Keywords:

• Krsticiella
• new combinations
• relict
• Alaska
• Beringia
• Siberia

Acknowledgements

The author thanks Dr Nina Lundholm and Christian Lange for the opportunity to study Foged’s material at the Algal herbarium of the Natural History Museum of Denmark, University of Copenhagen, and for the loan of three Foged’s samples. Eugene Potapov, Sergei, Galina, Nikita and Anastasia Zimov greatly helped with the field work in the Kolyma Lowland. The use of the Centralized Research Facilities, Drexel University for the SEM is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author.