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