The Diatom Attachment Scar Ophthalmichnus lyolithon igen. et isp. n.

Abstract

A number of benthic diatoms (including species of the genera Cocconeis, Achnanthes, and Amphora) etch shallow attachment scars in carbonate hard substrates. The morphology of these microbioerosion traces mirrors the elliptical to biconvex outline of the diatoms, which, in its most common appearance, is expressed as a distinct ring-shaped groove. The traces are established as new ichnogenus and -species Ophthalmichnus lyolithon. The diatoms are assumed to form the etching scars by means of their adhesive mucilage composed of acidic polysaccharides, probably in order to enhance adhesion.

Keywords:

• Benthos
• Diatoms
• Biofouling
• Bioerosion
• Attachment
• Ichnotaxonomy
• Fixichnia

ACKNOWLEDGMENTS

We gratefully acknowledge J. Titschack (MARUM, Bremen) who provided the Rhodes shell material bearing the holotype, and I. Pyko (Oldenburg) who produced the SEM images of the Peloponnese material. S. Teichert (SENCKENBERG am Meer, Wilhelmshaven) advised with respect to proper ancient Greek. We want to thank M. A. Harper and P. E. Hargraves for her inspiring thoughts about the topic. The taxonomic identification of the trace making diatoms greatly profited from the advice of Diatom-L list members, especially M. A. Harper, F. A. S. Sterrenburg, M. J. Sullivan, and A. Witkowski. F. Hinz kindly helped to get original literature. The comments of two anonymous referees helped improving the manuscript.