Eurygonum nodosum Schmidt, 1992

Description: The borings consist of a three-dimensional network of galleries, about 4-6 µm in diameter, with dichotomous branching and diagnostic lateral nodular appendices or swellings of 4-8 µm in size (Fig. 4E-G). Bifurcations in various angles are common and the terminations of the galleries are round to blunt. The networks may extend several 100 µm into the substrate with a decreasing density and less branching points (Fig. 3A), whereas initial colonies run more closely parallel to the substrate surface (Fig. 4E).

Original ichnospecies diagnosis: Horizontal, threedimensional, multi-axial galleries with dichotomous bifurcations, terminal swellings and lateral appendices (after Schmidt 1992).