Biddulphia or Odontella? a comparative guide on the morphology of the genera of benthic mediophyte diatoms

Description: The systematics and taxonomy of the genera of the Biddulphiales and Eupodiscales have slowly been reorganized to better represent the scope of their frustule morphology. While taxonomic synonymies are littered across the genera, particularly Odontella Agardh, Triceratium Ehrenberg and Biddulphia Gray, SEM-assisted morphological surveys have helped immensely to sort out these genera by shared frustule characters rather than gross valve morphology. This talk will describe and discuss some of the diagnostic characters and character combinations to help researchers distinguish between some of the genera most common to North American waters.

Target Audience: This presentation is aimed at anyone interested in learning about the diatoms historically identified as Biddulphia or Triceratium, are interested in a refresher on frustule ultrastructure and terminology or would just like to see micrographs of some really visually striking diatoms.

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Ashworth, M. P., Nakov, T., and Theriot, E. C. (2013). Revisiting Ross and Sims (1971): toward a molecular phylogeny of the Biddulphiaceae and Eupodiscaceae (Bacillariophyceae). Journal of Phycology 49(6): 1207-1222.

Sims, P. A., Williams, D. M. and Ashworth, M. (2018). Examination of type specimens for the genera Odontella and Zygoceros (Bacillariophyceae) with evidence for the new family Odontellaceae and a description of three new genera. Phytotaxa 382(1); 1-56.