Chapter 3: Ichnology: Trace Fossils

1. Arthrophycus is a "worm" burrow exhibiting transverse ridges in a pattern so distinctive that the trace is given a formal taxonomic name. Examine the rock sample and present an analysis of where and how the original organism lived relative to the sediment substrate. Which ethological group (i.e. repichnial, cubichnial, etc.) would you place this ichnofossil in?

 

 

 

 

 

2. With the understanding that this is a Recent mollusc shell, describe briefly what this shell is undergoing. The numerous pock marks may be attributable to clionid sponges. What ecological role is being fulfilled and what bearing does this have on the fossilization potential of similar, but ancient examples?

 

 

 

 

 

3. Within which behavioral category would you place this trace fossil and why? What are the "nested U" structures found in this specimen called and how were they formed?

 

 

 

 

 

4. Using your notes, this chapter, displays, etc., name and sketch a trace fossil that you would expect to find in a deep water, bathyal environment. Explain why you would expect to find your trace in this particular environment. Do the same for a trace fossil you would expect to find in a neritic, subtidal, well aerated environment.

 

 

 

 

 

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