Dimorphichnus Seilacher, 1955

Description. The trail is 8 cm long and 6 8 cm wide and consists of two parallel series of well devel oped ridges 2 5 to 3 cm apart preserved on the sole of a bed One series consists of short 12 to 1 5 cm long ridges and the other of long up to 34 cm ridges The short ridges are parallel and straight at an angle of about 500 to the central axis of the trace and may be arranged in pairs The long ridges are less regular and are gently curved through 500 towards the center of the trace.