ABSTRACT
Trace fossils, sedimentary structures resulting from animal activity, cannot compete with body fossils when it comes to taxonomic resolution. Traces, or 'Lebensspuren', also have the advantage that they cannot be reworked to become redeposited outside the original habitat or as ghost fossils in deposits of much younger age. It is for these properties that as biogeologists we use trace fossils primarily to register changes in environmental parameters such as water depth, oxygenation, turbulence or productivity through stratigraphic time and space. In order to understand trilobite trace fossils, we must first discuss details of the trilobite feeding process. They can be derived from general features of trilobite construction and from the fact that the legs did not dig the sediment away from underneath the body. In order to meet typical Ordovician trace fossils, we have to turn to Jebel Uweinat in the extreme southwest of Egypt.
