Gyrochorte comosa Heer, 1865

Diagnosis. Wall-like burrow with a top part (positive epirelief) consisting of two convex lobes with a median furrow and a bottom part (negative hyporelief ) consisting of two grooves and a median ridge. The lobes on the top (and more rarely the grooves at the base) commonly exhibit transverse meniscus-like discontinuities and often obliquely aligned plaits. Internal structure (when recognizable) consists of repetitive biconvex-up modular units (spreiten). Burrows exhibit an irregular meandering or arcuate course, but more rarely they may be straight or gently curved (emended by Gibert and Benner, 2002).