Protichnites

Protichnites tracks from the late Cambrian of central Wisconsin

Protichnites is a genus of trace fossil consisting of the imprints made by the walking activity of arthropods. It is likely that more than one type of arthropod was responsible for these tracks. Euthycarcinoids, aglaspidids (see Aglaspida) and eurypterids are possible contributors. Protichnites consists of two rows of tracks and a linear depression between the two rows. This depression, which may be broken, set at an angle, and of varying width and depth, is thought to be the result of a dragging tail. The structures bearing this name were typically made on the tidal flats of Paleozoic seas, but similar ones extend into the Cenozoic. Its occurrence in late Cambrian sandstones of Canada and northern United States is evidence of some of the first life on land.

References

• Stephen P. Hesselbo (1989). "Trace fossils of Cambrian aglaspidid arthropods". Lethaia 21 (2): 129–146. doi:10.1111/j.1502-3931.1988.tb02064.x. 
• C. T. Hoxie & J. W. Hagadorn (2005). "Late Cambrian arthropod trackways in subaerially exposed environments". Geological Society of America Abstracts with Programs, Northeastern Section 37: 12. 
• N. E. Vaccari, G. D. Edgecombe & C. Escudero (2004). "Cambrian origins and affinities of an enigmatic fossil group of arthropods". Nature 430 (6999): 554–557. doi:10.1038/nature02705. PMID 15282604. 

External links

• Includes additional photographs and information on Protichnites from the exceptional Blackberry Hill localities; in Italian, but can be translated using Babel Fish.
• Discusses a major source of Protichnites tracks.