Borings in solitary rugose corals of the Selkirk Member, Red River Formation (late Middle or Upper Ordovician), southern Manitoba

Borings occur in solitary rugose corals from the Selkirk Member of the late Middle or Upper Ordovician Red River Formation in southern Manitoba. They are assigned to Dictyoporus garsonensis n. ichnosp., which was produced by algae, and Trypanites weisei Mägdefrau 1932, made by spionid polychaete annelids. Most, and possibly all, boring occurred while the host corals were alive and in life position. The location and relative abundance of borings support interpretations that unattached curved solitary corals lay with the convex cardinal side in the sediment and the concave counter side facing upward during life, whereas straight conical forms were oriented upright in the sediment. These ichnospecies suggest that host corals lived in very shallow marine environments.