Ichnofossils

Arenicolites Salter, 1857

Taxon description

Knaust, 2017

Morphology, Fill and Size: Arenicolites refers to unbranched U-shaped burrows having a subvertical orientation, with or without lining and passive fill (Rindsberg and Kopaska-Merkel 2005; Bradshaw 2010).

Díez-Canseco et al., 2016

Description.—Straight cylindrical burrows, unbranched and oriented perpendicular to inclined to the bedding plane, commonly seen as paired circular openings at the top of the layers. Lined wall and massive fill contrasting with the host rock. Diameter is 3.4–30 mm. Preserved as negative epirelief and exceptionally as full relief. Cross-section views are rarely observed and depth is difficult to measure. Maximum observed length is 70mm.

Ethology and tracemaker.—Arenicolites is a dwelling trace (domichnion) produced by suspension-feeding worms (Häntzschel, 1975) or by detritus and deposit-feeding worms, particularly polychaetes (e.g., Bromley, 1996). In modern environments, similar burrows are produced in coastal environments by deposit-feeding polychaetes of the families Spionida (e.g., Gingras et al., 1999) and Carpitellida (e.g.,Dashtgard, 2011), as well as by suspension-feeding amphipod crustaceans and deposit-feeding sipunculids (e.g., Baucon and Felletti, 2013).

Bradshaw, 2010

Diagnosis: Simple U-tubes without spreite, perpendicular to bedding plane; varying in size, tube diameter, distance of limbs
and depth of burrows; limbs rarely somewhat branched, some with funnel-shaped opening; walls commonly smooth, occasionally
lined or sculptured; burrows may reach considerable depth (Häntzschel, 1975).

Mángano et al., 2002a

Simple, U-shaped, vertical burrows without spreiten. Walls are smooth with thin lining. Burrow fill is identical to host rock. Burrow depth is 17.2-40.0mm; arm width is 4.0-11,4mm; spacing between is arms 71.4-201.7mm. Preserved as full relief.

Selection of related publications
Toom, U., Vinn, O. & Hints, O. 2018. Ordovician and Silurian ichnofossils from carbonate facies in Estonia: A collection-based review. Palaeoworld , 1-22. DOI:10.1016/j.palwor.2018.07.001
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
Mikuláš R. & Dronov, A. V. 2005. Trace fossils. The Sixth Baltic Stratigraphical Conference. Cambrian and Ordovician of St. Petersburg Region, Guidebook for the pre-conference field trip. Dronov, A.V., Tolmacheva T., Raevskaya E. (Eds.), pp. 33-38.
Knaust, D. 2004. Cambro-Ordovician trace fossils from the SW-Norwegian Caledonides. Geological Journal 39, 1, 1-24. DOI:10.1002/gj.941
Dam, G. & Andreasen, F. 1990. High-energy ephemeral stream deltas; an example from the Upper Silurian Holmestrand Formation of the Oslo Region, Norway. Sedimentary Geology 66, 3-4, 197-225. DOI:10.1016/0037-0738(90)90060-7