Editing Trace fossil (section)

=== Stratigraphic correlation ===
Some trace fossils can be used as local [[index fossil]]s, to date the rocks in which they are found, such as the burrow ''[[Arenicolites]] franconicus'' which occurs only in a {{convert|4|cm|in|frac=2|abbr=on}} layer of the [[Triassic]] [[Muschelkalk]] epoch, throughout wide areas in southern [[Germany]].<ref name=Schlirf2006>{{cite journal
 | author = Schlirf, M.
 | year = 2006
 | title = ''Trusheimichnus'' New Ichnogenus From the Middle Triassic of the Germanic Basin, Southern Germany
 | journal = Ichnos
 | volume = 13
 | issue = 4
 | pages = 249–254
 | doi = 10.1080/10420940600843690
| s2cid = 129437483
 }}</ref>

The base of the [[Cambrian]] period is defined by the first appearance of the trace fossil ''[[Treptichnus pedum]]''.<ref>{{Cite journal
  | last1 = Gehling
  | first1 = James
  | last2 = Jensen
  | first2 = Sören
  | last3 = Droser
  | first3 = Mary
  | last4 = Myrow
  | first4 = Paul
  | last5 = Narbonne
  | first5 = Guy
  | title = Burrowing below the basal Cambrian GSSP, Fortune Head, Newfoundland
  | journal = Geological Magazine
  | volume = 138
  | issue = 2
  | pages = 213–218
  |date=March 2001
  | doi = 10.1017/S001675680100509X
| bibcode = 2001GeoM..138..213G
  | s2cid = 131211543
 }}
</ref>

Trace fossils have a further utility, as many appear before the organism thought to create them, extending their stratigraphic range.<ref name=Seilacher1994>e.g. {{cite journal
 | author = Seilacher, A.
 | year = 1994
 | title = How valid is ''Cruziana'' Stratigraphy?
 | journal = International Journal of Earth Sciences
 | volume = 83
 | issue = 4
 | pages = 752–758
 | doi=10.1007/BF00251073
 | bibcode=1994GeoRu..83..752S
| s2cid = 129504434
 }}</ref>