Davidharwoodia megaspina gen. et sp. nov. (Corethrales), a new fossil marine diatom genus from Mors, Jutland (early Eocene)

Abstract

A taxonomic survey of the early Eocene diatomites of Mors has revealed a new member of the Corethrales, Davidharwoodia megaspina gen. et sp. nov., which is the first fossil Corethron-like diatom to possess backward-pointing spines. The new species is presumably heterovalvate, with a rounded pyramidal Type 1 valve bearing a single huge leaf-shaped spine (and corresponding large socket) in addition to the narrower spines, and a more elongate helmet-shaped Type 2 valve possessing spines of a different design and twice as many sockets of equal size. The genus can be distinguished from Micrampulla by lacking the large inflated structures emanating from the dome, from Praecorethron by a narrower marginal area and vertically placed sockets, and from Corethron by lacking hooked spines.

Keywords:

• articulated spines
• Corethron
• diatomite
• evolution
• Fur Formation
• heterovalvy

Acknowledgements

Richard M. Crawford and Friedel Hinz (formerly of the Hustedt Collection in the Alfred-Wegener-Institute in Bremerhaven) are thanked for providing the samples used in this study. The manuscript benefited from discussion with David Harwood during the early phase of this research. The authors would also like to thank the reviewers and editors, whose suggestions greatly improved the quality of the text.

Disclosure statement

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

Additional information

Funding

This research benefited from a Japan Society for the Promotion of Science (JSPS) KAKENHI Grant (Number 19K06820), awarded to RWJ.