Ichnofossils

Chondrites Sternberg, 1833

Taxon description

Knaust, 2017

Morphology, Fill and Size: Chondrites is one of the most common and widely distributed trace fossils; due to its rootlike appearance it was originally interpreted as a plant fossil.  It consists of tunnel systems possessing a single or a small number of master shafts, presumably open to the surface, which ramifies with depth under acute angle to form a dendritic or root-like system (Osgood1970; Fu1991). Most of the burrows show an active fill,sometimes with portions preserving a meniscate structure.The burrows are unlined. The tunnel diameter remains constant in different parts of the burrow and typically is in the range of less than 1 mm to a few millimeters.

Fernández & Pazos, 2012

Remarks. Chondrites is ethologically classified as a feeding trace (fodinichnia). It is generally assigned to depositivorous and/or suspensivorous annelids or sipunculids.

Mángano et al., 2002a

Recent work suggests that Chondrites may represent specialized feeding behavior that involves chemosymbiosis, being interpreted as a sulfide pump (Fu, 1990, Seilacher, 1990; Bromley, 1996). It has been regarded that the Chondrites animal developed adaptations to cope with oxygen-depleted conditions (Bromley & Ekdale, 1984; Savdra, 1992).

Howard & Frey, 1984

Diagnosis: Dendritic, smooth walled, regularly but asymmetrically branched small burrow systems that ordinarily do not interpenetrate or interconnect. Diameter of components within a given system remains more or less constant.

Selection of related publications
Toom, U., Vinn, O., Hints, O. 2019. Ordovician and Silurian ichnofossils from carbonate facies in Estonia: A collection-based review. Palaeoworld 28, 1-2, 123-144. 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. 6th Baltic Stratigraphical Conference. Cambrian and Ordovician of St. Petersburg Region. Guidebook of the pre-conference field trip, pp. 33-38.
Elias, R. J., Nowlan, G. S., Bolton, T. E. 1988. Paleontology of the type section, Fort Garry Member, Red River Formation (Upper Ordovician), southern Manitoba.