Fig. 28. Rhopalondendrina acanthina igen. et isp. nov. A in Taming an ichnotaxonomical Pandora's box: revision of dendritic and rosetted microborings (ichnofamily: Dendrinidae)

Fig. 28. Rhopalondendrina acanthina igen. et isp. nov. A. SEM of holotype, partly obscured by other microborings, with point of entry at the lower left, in an epoxy cast of a Middle Pleistocene bivalve shell from the Island of Rhodes, Greece. B–C. Planar and oblique views of the paratype, illustrating an early ontogenetic stage with short vertical entrance tunnel; same epoxy cast as the holotype. D–F. SEM of three different ontogenetic stages (arrows indicating initial points of entry), in epoxy casts from experimental bivalve shells deployed at Faial Island in the Azores (same for G–I). G. Oblique view of a specimen with vertical entrance tunnel and short spiny protrusions connecting the trace to the substrate surface. H–I. Two specimens of a related dendrinid from the Azores experiment, awaiting ichnotaxonomical treatment as soon as more material becomes available.