Morphology and taxonomy of an almost forgotten fossil diatom, Gaillonella sculpta Ehrenberg (Bacillariophyceae)

Abstract

Type material of Melosira sculpta (Ehrenberg) Kützing from the Ehrenberg Collection was studied using light (LM) and scanning electron (SEM) microscopy. Comparison with Pseudoaulacosira moisseeviae (Lupikina in Brattseva et al.) Lupikina & Khursevich showed that they have very similar valve morphologies and should both belong to Pseudoaulacosira Lupikina & Khursevich. However, the species differ morphologically in several characters and so a new combination, Pseudoaulacosira sculpta (Ehrenberg) Usoltseva & Houk comb. nov. is proposed. Morphological and ultra-morphological features of this species are presented and discussed, including the presence of a septum.

Keywords:

• Bacillariophyceae
• Miocene
• Gaillonella
• Pseudoaulacosira
• taxonomy
• valve ultrastructure

Acknowledgements

We wish to thank to Dr. David Lazarus, curator of the Ehrenberg Collection, Humboldt University of Berlin, Germany, for his kind help with material. We would like to thank Victor Egorov for his assistance during the work on SEM. We would also like to thank to Dr. Bánk Beszteri and Friedel Hinz (Hustedt Collection, Alfred Wegener Institute for Polar and Marine Research (BRM), Bremerhaven, Germany) for their hospitality and help during our investigations in the Diatom Collection of Friedrich Hustedt. This work was carried out as part of the project no. VI.50.1.3 (0345–2014-0001) in the Electron Microscopy Center of Collective Instrumental Center ‘Ultra microanalysis’ at the Limnological Institute of the Siberian Branch of the Russian Academy of Sciences.

Disclosure statement

No potential conflict of interest was reported by the authors.