Ichnofossils

Helminthoidichnites Fitch, 1850

Taxon description

Hanken et al., 2016

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).

Uchman et al., 2005b

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).

Schlirf et al., 2001

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.

Buatois et al., 1998c

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.

Selection of related publications
Hanken, N.-M., Uchman, A., Nielsen, J. K., Olaussen, S., Eggebø, T., Steinsland, R. 2016. Late Ordovician trace fossils from offshore to shallow water mixed siliciclastic and carbonate facies in the Ringerike Area, Oslo Region, Norway. Ichnos 23, 3-4, 189-221. DOI:10.1080/10420940.2016.1199427
Uchman, A., Hanken, N.-M., Binns, R. 2005. Ordovician Bathyal Trace Fossils From Metasiliciclastics in Central Norway and Their Sedimentological and Paleogeographical Implications. Ichnos 12, 2, 105-133. DOI:10.1080/10420940590914534
Jensen, S. 1997. Trace fossils from the Lower Cambrian Mickwitzia sandstone, south-central Sweden. Fossils and Strata 42, 1-110.
Crimes, T. P. 1992. Changes in the trace fossil biota across the Proterozoic-Phanerozoic boundary. Journal of the Geological Society 149, 4, 637-646. DOI:10.1144/gsjgs.149.4.0637