Ophiomorpha are dwelling burrows formed by suspension-feeding shrimp. They are distinguished from other burrows by the irregular pelleted outer lining. These burrows are created by the shrimps enforcing the burrow by packing feces along the walls. The lining is smooth on the inside and is usually similar in composition to the host rock. These types of dwelling burrows occur with Skolithos burrows in shoreface environments, brackish waters, and environments with sandy substrates, like estuaries and tidal shoals.