Editing Trace fossil (section)

==Other notable trace fossils==
Less ambiguous than the above ichnogenera, are the traces left behind by [[invertebrate]]s such as ''[[Hibbertopterus]]'', a giant "sea scorpion" or [[eurypterid]] of the early [[Paleozoic]] era. This marine [[arthropod]] produced a spectacular track preserved in Scotland.<ref>{{cite journal|author=Whyte, MA |year=2005 |title=Palaeoecology: A gigantic fossil arthropod trackway |journal=Nature|volume=438|pages=576 |doi=10.1038/438576a|pmid=16319874|issue=7068|bibcode = 2005Natur.438..576W |s2cid=4422644 |doi-access=free }}</ref>

[[Bioerosion]] through time has produced a magnificent record of borings, gnawings, scratchings and scrapings on hard substrates. These trace fossils are usually divided into macroborings<ref>Wilson, M.A., 2007. Macroborings and the evolution of bioerosion, pp. 356–367. In: Miller, W. III (ed.), Trace Fossils: Concepts, Problems, Prospects. Elsevier, Amsterdam, 611 pages.</ref> and microborings.<ref>Glaub, I., Golubic, S., Gektidis, M., Radtke, G. and Vogel, K., 2007. Microborings and microbial endoliths: geological implications. In: Miller III, W (ed) Trace fossils: concepts, problems, prospects. Elsevier, Amsterdam: pp. 368–381.</ref><ref>Glaub, I. and Vogel, K., 2004. The stratigraphic record of microborings. Fossils & Strata 51:126–135.</ref> Bioerosion intensity and diversity is punctuated by two events. One is called the Ordovician Bioerosion Revolution (see Wilson & Palmer, 2006) and the other was in the Jurassic.<ref>Taylor, P.D. and Wilson, M.A., 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1–103.{{cite web |url=http://www3.wooster.edu/geology/Taylor%26Wilson2003.pdf |title=Archived copy |access-date=2009-07-21 |archive-url=https://web.archive.org/web/20090325233234/http://www.wooster.edu/geology/Taylor%26Wilson2003.pdf |archive-date=2009-03-25 }}</ref> For a comprehensive bibliography of the bioerosion literature, please see the External links below.

The oldest types of [[tetrapod]] tail-and-footprints date back to the latter [[Devonian]] period. These [[vertebrate]] impressions have been found in [[Ireland]], [[Scotland]], [[Pennsylvania]], and [[Australia]]. A sandstone slab containing the track of tetrapod, dated to 400 million years, is amongst the oldest evidence of a vertebrate walking on land.<ref name="Vickers-Rich1993">{{cite book |last1=Vickers-Rich |first1=P. |title=Wildlife of Gondwana |date=1993 |publisher=Reed |location=NSW |isbn=0-7301-0315-3 |pages=103–104}}</ref>

Important [[human evolution|human]] trace fossils are the [[Laetoli]] ([[Tanzania]]) footprints, imprinted in volcanic ash 3.7 [[annum|Ma]] (million years ago) – probably by an early [[Australopithecus]].<ref name=RaichlenEtal1010>{{Cite journal|year=2010 |author=David A. Raichlen |author2=Adam D. Gordon |author3=William E. H. Harcourt-Smith |author4=Adam D. Foster |author5=Wm. Randall Haas Jr |title=Laetoli Footprints Preserve Earliest Direct Evidence of Human-Like Bipedal Biomechanics |journal=PLOS ONE |volume=5 |issue=3 |page= e9769 |doi=10.1371/journal.pone.0009769|pmid=20339543|pmc=2842428|editor1-last=Rosenberg|editor1-first=Karen|bibcode=2010PLoSO...5.9769R |doi-access=free }}</ref>