The grooves on the upper surface of sandstones beds are about 1 mm wide, semioval in cross section, straight or slightly curved. They bifurcate and cross each other forming irregular polygons. Indistinct transverse furrows on some specimens resemble the backfill type of burrow infilling and are suggestive of peristaltic locomotion mechanism of the animal. Width of a single polygon varies from 2 to 5 cm. Concave epireliefs.