Hillichnus Bromley, Uchman, Gregory et Martin 2003

Diagnosis : Complex trace fossil comprising several contrasting parts. Two concentric structures, a basal segmented structure and within this a basal tube, run axially along the base and give rise to lateral spreiten or feather-like structures. The individual spreiten or feather-like structures arise alternately on either side of the basal segmented structure. Arising by branching from the basal tube, a series of sand- and mud-lined tubes curve upward into a nearly vertical position. These rising tubes may stand in a straight line, as a zigzag line, or in irregular groups. The general course of the trace fossil is horizontal, straight to curving or rarely looping.