Different forms of trace fossils of the Glossifungites facies.  Since these
occur in a hard unlithified substrates they indicate a shallow marine coast
where wave erosion can expose this surface. (Frey and Pemberton, 1984)

Trilobite trace fossils

There are lots of of ichnofossil types, that are classified on their part regarding drifferent criterions, thus divided into higher- ranking groups. For deion and interpretation of trace fossils, the ethological classification (A. Seilacher, Müller) is consulted. Compared to the sedimental classification, here the classification (11 divisions) results from the behavioral pattern of animals. The behavior patterns of capital importance of trilobites are characterised by the following ichnofossils. The following graphic, abandoned to me by Dr. S. M. Gon III to referring illustration,  THANKS SAM :-), displays the essential behavioral pattern of trilobites:

Source:  © Dr. S. M. Gon III,  A Guide to the Orders of trilobites

http://www.trilobites.info

What are Ichnofossils actually

(Ichnofossils- (Gr.) footstep, track)

As a matter of principle, ichnology (track analysis) circumstantiates different behaviours of living organisms (recent or fossil). For this, ichnology analyzes the so- called life trails of this organisms. This life trails, also- known as trace fossils, are marks or shapes, engraved to abiotic substrate by organisms manifestations of life, like motion, resting phases or also hunting activities. It"s rather possible to ascribe to origin"s behaviour than to origin itself. Though similar traces can be created by different species. It"s also possible, that identical signs of live, created by a species, may have deviant behaviours in different habitats. Thus allows  very interesting insights on ecology and behaviors of an extincted animal. Regarding our favourite invertebrates, we"re especially interested in that exogenous traces at sediments surface, arised from manifestations of life on trilobites normal course of life the ichnofossils

Bioturbation

Any animal that lives in or on sediments – that digs or burrows or simply moves across the surface – will create some kind of disturbance in those sediments.

In the broadest sense, any kind of sediment disturbance is bioturbation. Often, however, the term is employed more restrictively to refer to the disruption of fine sedimentary layering by digging organisms.