Genus

Phycodes Richter, 1850

Taxon description

Hammersburg et al., 2018

Diagnosis.—Horizontal to subhorizontal, cylindrical to U-shaped burrows with dichotomously branched tunnels forming bundles (Fillion & Pickerill, 1990; Knaust, 2007).

Hanken et al., 2016

Diagnosis. Horizontally bundled burrows preserved outwardly as convex hyporeliefs. Overall, the pattern is reniform, fasciculate, flabellate, broomlike, ungulate, linear, falcate, or circular. Most forms consist of a single or a few main branches showing a spreite structure that
give rise distally to numerous free branches. In other forms, the spreiten are lacking and branching tends to be secondary or more random. Individual branches are terete and finally annulate or smooth (after Han and Pickerill, 1994, based on Osgood, 1970, and Fillion and Pickerill, 1990).

Remarks. Seilacher (2007) confined Phycodes to tightly spaced bundles. Phycodes is regarded as a feeding structure produced by unknown organisms. In the Paleozoic, it is known mostly from shallow-marine sediments.For discussion of this ichnogenus, see Osgood (1970), Fillion and Pickerill (1990), Han and Pickerill (1994), and Seilacher (2000).

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
Knaust, D. 2004. Cambro-Ordovician trace fossils from the SW-Norwegian Caledonides. Geological Journal 39, 1, 1-24. DOI:10.1002/gj.941
Seilacher, A. 2000. Ordovician and Silurian Arthrophycid Ichnostratigraphy. Geological Exploration in Murzuq Basin, pp. 237-258. Elsevier. DOI:10.1016/B978-044450611-5/50013-1
Jensen, S., Grant, S. W. F. 1998. Trace fossils from the Dividalen Group, northern Sweden: implications for Early Cambrian biostratigraphy of Baltica. Norsk Geologisk Tidsskrift 78, 4, 305-317.
Jensen, S. 1997. Trace fossils from the Lower Cambrian Mickwitzia sandstone, south-central Sweden. Fossils and Strata 42, 1-110.
Clausen, C. K., Vilhjálmsson, M. 1986. Substrate control of lower Cambrian trace fossils from Bornholm, Denmark. Palaeogeography, Palaeoclimatology, Palaeoecology 56, 1-2, 51-68. Elsevier BV. DOI:10.1016/0031-0182(86)90107-0
Hofmann, H. J. 1979. Chazy (Middle Ordovician) trace fossils in the Ottawa - St. Lawrence Lowlands. Geological Survey of Canada Bulletin 321, 27-60. DOI:10.4095/106172