Ichnofossils

Oichnus Bromley, 1981

Taxon description

Buatois et al., 2017

2.63. Circular holes and pit-shaped borings

Wisshak et al., 2015

Circular to subcircular holes of biogenic origin bored into hard substrates. The hole may pass right through the substrate as a penetration, where the substrate is a thin shell; or end within the substrate as a shallow to deep depression or short, subcylindrical pit.

Knaust, 2012a

Unbranced, circular.

Nielsen & Nielsen, 2001

Ethology. Pit-shaped specimens of O. simplex and O. paraboloides have been interpreted as attachment scars (see Franzén, 1974; Brett, 1978, 1985) and may be categorized as domichnia. At least some specimens, especially those of O. paraboloides, were probably produced by potential predators and can be considered as "unfinished' praedichnia. Moreover many different species of benthic foraminiferans are known to be bioeroders (Vénec-Peyré, 1996) and very little knowledge exists as to the reasons for this behavior. At least some specimens of pit-shaped Oichnus may have been produced by sessile host-selective epibionts, probably parasites or commensal suspension-feeding animals of unknown affinities (Brett, 1978,1985).

Bromley, 1981a

Circular to subcircular holes of biogenic origin bored into hard substrates. The hole may pass right through the substrate as a penetration, where the substrate is a thin shell; or end within the substrate as a shallow to deep depression or short, subcylindrical pit.

Lévi, 1953

Tracemaker: They were probably produced by Muricidae and Marginellidae (gastropods) and octopod cephalopods, respectively.

Selection of related publications
Vinn, O., Holmer, L. E., Wilson, M. A., Isakar, M., Toom, U. 2021. Possible drill holes and pseudoborings in obolid shells from the Cambrian/Ordovician boundary beds of Estonia and the uppermost Cambrian of NW Russia. Historical Biology , 1-6. DOI:10.1080/08912963.2021.1878355
Bromley, R. G. 1981. Concepts in ichnology illustrated by small round holes in shells. Acta Geologica Hispanica 16, 1-2, 55-64.
References based on distribution