The nomenclature of trace fossils is based on the system used for naming biological groups,
but instead of genus and species the terms ichnogenus and
ichnospecies are used. However it must always be remembered that trace fossils are not
and never have been organic, they are inorganic structures produced by biotic activity.
In addition trace fossils should not be named based on any inferences about the producer of the structure, but simply using the morphology of the trace itself. Therefore one trace fossil group can have many different producers, and a single producer can make more than one type of trace fossil. Problems have arisen when ichnotaxa are based on notions about the producing organism. The ichnogenera Isopodichnus and Cruziana are morphologically identical, but are thought to be made by two different groups of organisms - one being freshwater, the other marine. This has led to Isopodichnus only being recognized by some ichnologists6. This is an example of only one of the problems which besets ichnotaxonomy, a field currently in a state of some confusion.
The trackways in this guide are all line drawings based on specimens figured in the Treatise on Invertebrate Paleontology, Part W Miscellanea, supplement 1: trace fossils and problematica 7. They are only examples of each ichnogenus, trackways display a great deal of morphological variation and often grade into each other.
Ichnogenera are grouped together here under most usual or most likely producer - trilobites, crustaceans, chelicerates, myriapods or insects. However as mentioned above, one ichnogenera can have multiple producers. A trackway being listed within a group does not necessarily mean it is only produced by that particular type of arthropod.
All scale bars on the figures are 1 cm.
Use the guide by clicking on one of the producers below: