Ichnofacies

An ichnofacies is an assemblage of trace fossils that provides an indication of the conditions that their formative organisms inhabited.

[1] Palaeontologist Adolf Seilacher pioneered the concept of ichnofacies, whereby the state of a sedimentary system at its time of deposition could be deduced by noting the trace fossils in association with one another.

[1] Ichnofacies can provide information about water depth, salinity, turbidity and energy.

[1] This is partly because of the relative abundance of suspended food particles, such as plankton, in the shallower waters of the photic zone, and partly because vertical burrows are more secure in the turbulent conditions of shallow water.

In deeper waters, there is a necessary transition to sediment feeding (extracting nutrients from the mud).