What is Burgess Shale?
[[File:Marella.png|thumb|right|230px|''[[Marrella]]'', the most abundant Burgess Shale organism]] [[File:Ottoia tricuspida ROM 63057.jpg|thumb|230px|right|''[[Ottoia]]'', a soft-bodied worm, abundant in the Burgess Shale]] [[File:ROM-BurgessShale-CompleteAnomalocarisFossil.png|thumb|230px|The first complete ''[[Anomalocaris]]'' fossil found]] The '''Burgess Shale Formation''' in the [[Rocky Mountains]] of [[British Columbia]] is one of the world's most celebrated fossil sites, the best of its kind.<ref name=Gabbott2001>{{Cite journal| last = Gabbott | first = Sarah E.| year = 2001| journal = Encyclopedia of Life Sciences| title = Exceptional preservation| doi = 10.1038/npg.els.0001622| isbn = 9780470016176}}</ref><ref>Burgess Shale fossils and their importance. ''The Burgess Shale Geoscience'' 2010. [http://burgess-shale.bc.ca./discover-burgess-shale/burgess-shale-fossils-and-their-importance]</ref> It is famous for the exceptional preservation of the soft parts of its fossils.<ref name=Briggs>Briggs D.E.G; Erwin D.H. & Collier F.J. 1995. ''Fossils of the Burgess Shale''. Washington: Smithsonian Inst Press. {{ISBN|156098659X}}</ref><ref>Conway Morris, Simon. ''The crucible of creation: the Burgess Shale and the rise of animals''.</ref> It is ~505 million years old (Middle [[Cambrian]]),<ref name=Butterfield2006>{{Cite journal| last = Butterfield | first = N.J.| year = 2006| title = Hooking some stem-group worms: fossil lophotrochozoans in the Burgess Shale| journal = BioEssays| volume = 28| issue = 12| pages = 1161–1166| doi = 10.1002/bies.20507 | pmid = 17120226| s2cid = 29130876}}</ref> one of the earliest soft-parts fossil beds. The rock unit is a black [[shale]], and crops out at a number of [[wikt:locality|localities]] near the town of Field in the Yoho [[National Park]]. The Burgess Shale was discovered by [[palaeontologist]] [[Charles Doolittle Walcott]] in 1909, towards the end of the season's fieldwork.<ref>Yochelson E.L. 1996. Discovery, collection, and description of the Middle Cambrian Burgess Shal