Treptichnus

Treptichnus; Temporal range:
	Burrows viewed from the side
	Burrows viewed obliquely
Trace fossil classification
Ichnogenus:	†Treptichnus; Miller, 1889
Ichnospecies
	†T. apsorum Rindsberg & Kopasa-Merkel, 2005; †T. bifurcus Miller, 1889; †T. pedum Seilacher, 1955;
Synonyms
	Phycodes; Manykodes; Trichophycus; Affinovendia;

Treptichnus (formerly named Phycodes, Manykodes by J. Dzik,^[2] and also known as Trichophycus^[3]) is the preserved burrow of an animal. As such, it is regarded as the earliest widespread complex trace fossil. Its earliest appearance, around 542 million years ago (mya),^[4] which was contemporaneous with the last of the Ediacaran biota, is used to help define the dividing line, considered geologically at 541 mya, between the Ediacaran and Cambrian periods.^[5]^[6] It is last seen in the fossil record during the Cenomanian (99.7 mya).^[1]

^ ^a ^b AK Rindsberg and DC Kopaska-Merkel. 2005. Treptichnus and Arenicolites from the Steven C. Minkin Paleozoic Footprint Site (Langsettian, Alabama, USA). Alabama Paleontological Society Monograph 1 : 121-141
^ ^a ^b DZIK, Jerzy (2005). "Behavioral and anatomical unity of the earliest burrowing animals and the cause of the "Cambrian explosion"" (PDF). Paleobiology. 31 (3): 503–521. doi:10.1666/0094-8373(2005)031[0503:BAAUOT]2.0.CO;2. S2CID 55910646.
^ ^a ^b See e.g. fossiilid.info: paleodiversity in Baltoscandia: Trichophycus pedum
^ Srivastava, Purnima (June 2012). "Treptichnus pedum: An Ichnofossil Representing Ediacaran - Cambrian Boundary in the Nagaur Group, the Marwar Supergroup, Rajasthan, India" (PDF). Proc. Indian Natl. Sci. Acad. 78 (2): 161–169. Retrieved April 8, 2016.
^ Subcommission on Neoproterozoic Stratigraphy - URL retrieved June 22, 2009
^ International Commission on Stratigraphy, International Chronostratigraphic Chart, 2012, http://www.stratigraphy.org/column.php?id=Chart/Time%20Scale

[Rindsberg2005-1] AK Rindsberg and DC Kopaska-Merkel. 2005. Treptichnus and Arenicolites from the Steven C. Minkin Paleozoic Footprint Site (Langsettian, Alabama, USA). Alabama Paleontological Society Monograph 1 : 121-141

[Dzik-2] DZIK, Jerzy (2005). "Behavioral and anatomical unity of the earliest burrowing animals and the cause of the "Cambrian explosion"" (PDF). Paleobiology. 31 (3): 503–521. doi:10.1666/0094-8373(2005)031[0503:BAAUOT]2.0.CO;2. S2CID 55910646.

[fossiilid-3] See e.g. fossiilid.info: paleodiversity in Baltoscandia: Trichophycus pedum

[PINSA-201206-4] Srivastava, Purnima (June 2012). "Treptichnus pedum: An Ichnofossil Representing Ediacaran - Cambrian Boundary in the Nagaur Group, the Marwar Supergroup, Rajasthan, India" (PDF). Proc. Indian Natl. Sci. Acad. 78 (2): 161–169. Retrieved April 8, 2016.

[5] Subcommission on Neoproterozoic Stratigraphy - URL retrieved June 22, 2009

[6] International Commission on Stratigraphy, International Chronostratigraphic Chart, 2012, http://www.stratigraphy.org/column.php?id=Chart/Time%20Scale

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