Arthrophycus Hall, 1852

Emended diagnosis. Subhorizontal to oblique, straightish to curved,bilaterally symmetrical burrows with arranged in an imbricate series of spoonlike pads; crosssection subquadrangular; burrows simple,sparsely branched, or densely branched in anoverlapping, fan-like pattern; lower half part ofburrow sheathed by outer zone of closely spacedpads of sediment; lower surface of burrow withclosely spaced transverse ridges, commonly withmedian groove.

Emended diagnosis:  Arthropycid burrows, 5-15 mm in diameter, which explore the sediment mainly in a horizontal fashion. Consequently, the teichichnoid structures are lower than their horizontal extensions and are mainly expressed as positive hyporeliefs.