Sulcichnus, Martinell & Domenech, 2009

Martinell, Jordi & Domènech, Rosa, 2009, Commensalism in the fossil record: Eunicid polychaete bioerosion on Pliocene solitary corals, Acta Palaeontologica Polonica 54 (1), pp. 143-154 : 146-148

Ichnogenus Sulcichnus ichnogen. nov.

Etymology: After the Latin word sulcus, groove.

Ichnospecies type: Sulcichnus maeandriformis ichnosp. nov.

Diagnosis.—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.

Remarks.— Sulcichnus have some similarities with the ichnogenera Maeandropolydora and Caulostrepsis . Bromley and D’Alessandro (1983: 293) amended the former description by Voigt (1965) and re−described Maeandropolydora as “Long cylindrical galleries having two or more apertures, running through the substrate sinuously or in irregular contortions. Galleries may run parallel in contact with each other in pairs, with or without fusion. Loose or tight loops may occur; the limbs of these may be connected by a vane or form a pouch”.

Diagnosis of Caulostrepsis refers to U−shaped borings that have a vane connecting the limbs of the U−boring ( Bromley 2004), with more or less complex designs ( Bromley and D’Alessandro 1983).

Both traces correspond to complete endogenic tunnels made by endobionts, whereas Sulcichnus is an epigenic groove—never a tunnel—excavated on the solid substrate by an epibiont. Maeandropolydora often appears in the fossil record as a sinuous groove in the substrate due to breakage or weathering of the gallery roof. In such cases, misidentification may have occurred, and further revision is needed.