Description. This is an endichnial, concave, slightly winding furrow, about 1 mm wide, running along the horizontal laminae in the sandstone. Helminthoidichnites Fitch,1850 displays only occasional loops, whereas in Gordia Emmons,1844 loops are the most characteristic feature. In contrast to these genera, Helminthopsis has no loops (Hofmann and Patel,1989).
Helminthoidichnites displays only occasional loops, in contrast to Gordia, in which loops are the most characteristic feature. Helminthopsis does not display loops at all (Hofmann and Patel, 1989). The differences between Helminthoidichnites and Gordia have been confirmed by computer analysis (Hofmann, 1990).
Diagnosis: Relatively thin, horizontal, irregularly meandering or winding trails with occasional loops.
Remarks: In contrast to Gordia EMMONS, in which loops are the most characteristic feature, and to Helminthopsis HEER, in which no loops occur (HOFMANN & PATEL 1989) Helminthoidichnites FITCH displays occasional loops.
Emended diagnosis.—Horizontal, small, thin, unbranched, simple, straight or curved to, more rarely, circular trails or burrows that commonly display overlap among specimens, but lack self-overcrossing.