Trichichnus Frey, 1970

DIAGNOSIS.—Branched or unbranched, hairlike, cylindrical to sinuous burrows distinctly less than 1.0 mm. in diameter, oriented at various angles with respect to bedding. Burrow walls more or less distinct, commonly lined with diagenetic minerals.
 

Trichichnus is a branched or unbranched, straight to winding, hair-like cylindrical structure, mostly 0.1–0.7 mm in diameter, commonly pyritized, oriented at various angles (mostly vertical) with respect to the bedding. The common pyritization is a particular feature of Trichichnus, which is generally absent in other trace fossils.