Irhopalia spinosa (Radtke et Golubic, 2005)

Diagnosis: The system develops parallel to the substrate surface, extending from the point of the initial entry by several irregularly branched segmented tunnels. Laterally widened tunnel segments, triangular or polygonal in outline are interconnected by narrow passages. They are connected to the substrate surface by numerous spiny attachments

Description. This small Rhopalia ichnospecies is characterised by a substrate-parallel multibranched boring system with individual flattened chambers being interconnected by short galleries (Fig. 7A-B). Both the chambers and the interconnecting tunnels are connected to the substrate surface by short, tapering rhizoidal appendages. Individual, often elongate cavities are 6-12 µm wide and the interconnecting passages measure 2-4 µm in circular diameter.