The trace fossil Diopatrichnus santamariensis nov. isp. : a shell armored tube from Pliocene sediments of Santa Maria Island, Azores (NE Atlantic Ocean)

Diopatrichnus santamariensis nov. isp. from lower Pliocene sediments on Santa Maria Island in the Azores Archipelago (mid-North Atlantic) represents the third ichnospecies of Diopatrichnus Kern, as characterized by a vertical or inclined tube armoured mainly by bivalve shells that are mostly perpendicular to the burrow axis and concave-upward. The polychaete Owenia (family Oweniidae) is favoured as its potential tracemaker based on recent analogues, as opposed to the alternative polychaete Diopatra (family Onuphidae). The tracemaker was able to cross oceanic depths, distances, and colonize mid-ocean island sediments. In general, including this example from Santa Maria Island, Diopatrichnus occurs mostly within the Skolithos and the Cruziana ichnofacies.