Diagnosis. Large, straight to irregularly bent, unlined boring of variable length entering the substrate perpendicular to subparallel; cross−section oval; roughly constant oval diameter; terminus tapered to rounded.
Description. From a single oval aperture, the unbranched borings are sharply incised in the dense host skeleton, showing no deflections of the host growth increments, and are filled with a micritic matrix (Figs. 3, 4). The borings enter the substrate in a perpendicular to subparallel manner and follow primarily a straight course but may as well slightly curve or undulate. Individual traces measure up to 120 mm in length with an oval cross−section of averaging 7 (min. 5) × 13 (max. 17) mm in diameter, with a max/min ratio in excess of 2/1. Individual borings have a tapered to rounded terminus. Due to the high−abundance of traces within the sample analysed, borings occasionally truncate each other, occasionally resembling a branching pattern. Neither scratch marks nor any internal lining were observed. An idealised schematic drawing of the trace is given in Fig. 8.