Description: Vertical U-shaped burrow with protrusive spreiten and broad base; tubes are not parallel to each other and their diameter is also variable (0.9 to 1.2 cm). The burrow penetrates 12 cm in the sediment; diameter of the tube increases downward and their maximum diameter (1.2 cm) was observed at the base of the burrow. Burrow filled sediments are darker than the host sediments but spreiten is light coloured.