Long grooves, sometimes branched, running along the surface substrate sinuously or in a contorted fashion. Grooves never run in parallel, and loose or tight loops may occur.

Unbranched, branched, groove.

Category of architectural design: 2.78. Elongate or branched attachment bioerosion traces.

Macroboring; substrate calcareous; tracemaker invertebrate.

Diagnosis: Shallow groove parallel to the columella and bending 90° close to the calyx, to form a deeper, ring-shaped groove (cited from Martinell and Domènech 2009).

Description: Shallow grooves (1 mm maximum in depth) that run more or less in parallel to the axis of the columella from close to the base of the corallite. They turn a sharp 90 to the left when reaching a point a few millimetres from the edge of the calyx, where they deepen (to some 2 mm) and run almost the whole of the perimeter of the corallite, thus taking on the appearance of a branding iron.