With Skolithos, an ichnoguild of trace fossils characterized by vertical or steeply inclined burrows with thick, knobbly walls. The interior of the burrow system is smooth. Ophiomorpha ranges from the Permian to the present day and is associated with arthropods (Arthropoda). Individual tubes have a diameter of 3–6 cm, and may be branched, with large, bulbous terminations.
Subjects: Earth Sciences and Geography.