Fascichnus bellafurca (Radtke, Glaub, Vogel et Golubic, 2010)

Diagnosis: Tunnels originating from a single point of entry into the substrate, repeatedly dichotomously branched, diverging to form two- and three-dimensional, initially circular and later hemispheric clusters.

Description: Clusters of borings 70–400μ m in diameter composed of repeatedly dichotomously branched tunnels. Tunnels radiate from a single point of entry and branch repeatedly dichotomously to form hemispherical clusters with up to 40 tips. Tunnels initially parallel to the substrate surface, later penetrating deeper into the substrate especially in central parts of the colonies. Ramifications of tunnels occur repeatedly at variable angles between 35 and 110°.The branches are often slightly narrower at the base, widening toward the next ramification. The tips are rounded, sometimes slightly swollen. Tunnel diameters are variable ranging from 3.23–10.62μm. The size variation within each colony is much narrower than between colonies, with a significant overlap.