View source for Maotianshan Shales

{{Short description|Series of Early Cambrian deposits in the Chiungchussu Formation in China}}
{{use dmy dates|date=August 2025}}
{{Infobox rockunit
| name           = Maotianshan Shale
| period         = Cambrian Stage 3
| age            = Cambrian Stage 3, [[Qiongzhusian age]] local stage<br>≤{{fossil range|518|ref=<ref name="Yang2018">{{Cite journal|last1=Yang|first1=C.|last2=Li|first2=X.-H.|last3=Zhu|first3=M.|last4=Condon|first4=D. J.|last5=Chen|first5=J.|date=2018|title=Geochronological constraint on the Cambrian Chengjiang biota, South China|journal=Journal of the Geological Society|language=en|volume=175|issue=4|pages=659–666|doi=10.1144/jgs2017-103|bibcode=2018JGSoc.175..659Y|s2cid=135091168|issn=0016-7649|url=http://nora.nerc.ac.uk/id/eprint/521412/1/2018-JGS-Chuan%20Yang%20et%20al.pdf|access-date=2019-12-12|archive-date=2022-10-09|archive-url=https://ghostarchive.org/archive/20221009/http://nora.nerc.ac.uk/id/eprint/521412/1/2018-JGS-Chuan%20Yang%20et%20al.pdf|url-status=live}}</ref>}}
| image          = Maotianshan shale outcrop.JPG
| imagesize      =
| caption        = Outcrop of the Maotianshan Shale, site of the discovery of the Chengjiang Biota
| type           = [[Member (geology)|Member]]
| prilithology   = [[Shale]]
| otherlithology = [[Mudstone]]
| unitof         = [[Chiungchussu Formation]]
| subunits       =
| underlies      =
| overlies       =
| thickness      = {{convert|50|m|ft|abbr=on}}
| area           = multiple {{convert|10000|km2|sqmi|abbr=on}}
| map            =
| map_caption    =
| location       =
| coordinates    = {{coord|26.7|N|108.4|E|display=inline}}
| paleocoordinates = {{coord|28.1|N|154.3|E|display=inline,title}}
| region         = [[Chengjiang County]], [[Yunnan]]
| country        = [[China]]
| extent         = <!--{{convert||mi|km}}-->
| namedfor       = Maotianshan Hill
| namedby        =
| year_ts        =
| location_ts    = Maotianshan Hill
| coordinates_ts = <!--{{coord|d|m|s|N|d|m|s|E|display=inline}} -->
| paleocoordinates_ts =
| region_ts      = [[Chengjiang County]], [[Yunnan]]
| country_ts     = [[China]]
| thickness_ts   = <!--{{convert||m|ft|-1}}-->
}}
{{CEXNAV}}
The '''Maotianshan Shales''' ({{zh|s=帽天山页岩|t=帽天山頁岩|p=Màotiānshān yèyán}}) are a series of [[Cambrian|Early Cambrian]] [[Shale|sedimentary deposits]] in the Chiungchussu Formation<ref>{{cite book | url = https://books.google.com/books?id=gUQMKiJOj64C&pg=PA338 | title = Origin and early evolution of the Metazoa | isbn = 978-0-306-44067-0 | author1 = Lipps, J. H. | author2 = Signor, P. W | year = 1992| publisher = Springer }}</ref> or '''Heilinpu Formation''',<ref>{{cite journal |last1=Hou |first1=Xianguang |last2=Bergström |first2=Jan |title=The Chengjiang fauna — the oldest preserved animal community |journal=Paleontological Research |date=2003 |volume=7 |issue=1 |pages=55–70 |doi=10.2517/prpsj.7.55|bibcode=2003PalRe...7...55H |doi-access=free }}</ref> famous for their ''[[Lagerstätte|Konservat Lagerstätte]]n'', deposits known for the exceptional preservation of fossilized organisms or [[Trace fossil|traces]]. The Maotianshan Shales form one of some 40 [[Cambrian fauna|Cambrian fossil]] locations worldwide, exhibiting exquisite preservation of rarely preserved, non-mineralized soft tissue, comparable to the fossils of the [[Burgess Shale]] of [[British Columbia]], Canada. They take their name from Maotianshan Hill ({{zh|t={{linktext|帽|天|山}}|s={{linktext|帽|天|山}}|p=Màotiānshān|labels=|l=Hat Sky Mountain}}) in [[Chengjiang County]], [[Yunnan]] Province, China,{{cn|date=August 2025}} and lies within the "[[Eoredlichia]]-[[Wutingaspis]] Zone" of [[South China]].<ref>{{cite web  | title=Flinders Ranges | website=UNESCO World Heritage Centre| date=21 April 2025 | url=https://whc.unesco.org/en/tentativelists/6524/ | archive-url=https://web.archive.org/web/20250630073835/https://whc.unesco.org/en/tentativelists/6524/ | archive-date=30 June 2025 | url-status=live | access-date=13 August 2025}}</ref> A {{convert|512|ha|adj=on}} site within this formation, known as the [[Chengjiang Fossil Site]], was listed as a [[World Heritage Site]] by [[UNESCO]] in 2012.<ref name=unescowhs>{{cite web | website=UNESCO World Heritage Centre | title=Chengjiang Fossil Site | url=https://whc.unesco.org/en/list/1388/ | archive-url=https://web.archive.org/web/20250724140824/https://whc.unesco.org/en/list/1388/ | archive-date=24 July 2025 | url-status=dead | access-date=14 August 2025}}</ref>

The most famous assemblage of organisms are referred to as the '''Chengjiang biota''' for the multiple scattered [[fossil]] sites in Chengjiang. The age of the Chengjiang Lagerstätte is locally termed [[Qiongzhusian age|Qiongzhusian]], a stage correlated to the late [[Atdabanian]] Stage in [[Siberia]]n sequences of the middle of the [[Early Cambrian]].<ref name=Xingliang2008>{{cite journal|last1=Zhang |first1=X. |last2=Liu |first2=W. |last3=Zhao |first3=Y. | date=2008 |title=Cambrian Burgess Shale-type Lagerstätten in South China: Distribution and significance |journal=Gondwana Research |volume=14 |issue=1–2 |pages=255–262 |doi=10.1016/j.gr.2007.06.008 |bibcode=2008GondR..14..255Z |citeseerx=10.1.1.852.2120 }}</ref><ref name=Rozanov2008>{{cite journal|last=Rozanov|first=A. Yu. |author2=Maoyan Zhu, K. L. Pak and P. Yu. Parkhaev|date=2008|title=The 2nd Sino-Russian Symposium on the Lower Cambrian Subdivision|journal=Paleontological Journal|volume=42|issue=4|pages=441–446|doi=10.1134/S0031030108040151|bibcode=2008PalJ...42..441R |s2cid=129626166 }}</ref>
The shales date to ≤{{ma|518}}.<ref name="Yang2018"/>

Along with the Burgess Shale, the Maotianshan Shales are remarked as "our best window into the [[Cambrian explosion|Cambrian 'explosion']]",<ref name=":02">{{Cite journal |last1=Shu |first1=D. G. |last2=Conway Morris |first2=S. |last3=Han |first3=J. |last4=Chen |first4=L. |last5=Zhang |first5=X. L. |last6=Zhang |first6=Z. F. |last7=Liu |first7=H. Q. |last8=Li |first8=Y. |last9=Liu |first9=J. N. |date=2001-11-22 |title=Primitive deuterostomes from the Chengjiang Lagerstätte (Lower Cambrian, China) |journal=Nature |volume=414 |issue=6862 |pages=419–424 |bibcode=2001Natur.414..419S |doi=10.1038/35106514 |issn=0028-0836 |pmid=11719797 |s2cid=4345484}}</ref> especially on the origin of [[chordates]].<ref name=":12">{{Cite journal |last=McMenamin |first=Mark A. S. |date=2019 |title=Cambrian Chordates and Vetulicolians |journal=Geosciences |language=en |volume=9 |issue=8 |pages=354 |bibcode=2019Geosc...9..354M |doi=10.3390/geosciences9080354 |issn=2076-3263 |doi-access=free}}</ref>

== History and scientific significance ==
Although fossils from the region have been known from the early part of the 10th century, Chengjiang was first recognized for its exquisite states of preservation with the 1984 discovery of the [[naraoiidae|naraoiid]] ''[[Misszhouia]]'', a soft-bodied relative of [[trilobite]]s. Since then, the locality has been intensively studied by scientists throughout the world, yielding a constant flow of new discoveries and triggering an extensive scientific debate surrounding the interpretation of discoveries. Over this time, taxa have been revised or reassigned to different groups. Interpretations have led to many refinements of the [[phylogeny]] of groups<ref>{{Cite journal |last1=Saleh |first1=Farid |last2=Ma |first2=Xiaoya |last3=Guenser |first3=Pauline |last4=Mángano |first4=M. Gabriela |last5=Buatois |first5=Luis A. |last6=Antcliffe |first6=Jonathan B. |date=2022-08-23 |title=Probability-based preservational variations within the early Cambrian Chengjiang biota (China) |journal=PeerJ |language=en |volume=10 |article-number=e13869 |doi=10.7717/peerj.13869 |doi-access=free |pmid=36032952 |pmc=9415357 |issn=2167-8359}}</ref><ref>{{Cite journal |last1=Xianguang |first1=Hou |last2=Ramsköld |first2=Lars |last3=Bergström |first3=Jan |date=1991 |title=Composition and preservation of the Chengjiang fauna –a Lower Cambrian soft-bodied biota |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1463-6409.1991.tb00303.x |journal=Zoologica Scripta |language=en |volume=20 |issue=4 |pages=395–411 |doi=10.1111/j.1463-6409.1991.tb00303.x |issn=0300-3256|url-access=subscription }}</ref> and even the erection of the new phylum [[Vetulicolia]] of primitive [[deuterostomes]].<ref name=":2">{{Cite journal |last=Shu |first=Degan |date=2005 |title=On the Phylum Vetulicolia |url=http://link.springer.com/10.1007/BF03183746 |journal=Chinese Science Bulletin |language=en |volume=50 |issue=20 |pages=2342–2354 |bibcode=2005ChSBu..50.2342S |doi=10.1007/BF03183746 |issn=1001-6538 |s2cid=86827605|url-access=subscription }}</ref><ref name=":3">{{Cite journal |last1=Briggs |first1=Derek E. G. |last2=Fortey |first2=Richard A. |date=2005 |title=Wonderful strife: systematics, stem groups, and the phylogenetic signal of the Cambrian radiation |url=https://www.cambridge.org/core/product/identifier/S0094837300025331/type/journal_article |journal=Paleobiology |language=en |volume=31 |issue=2_Suppl |pages=94–112 |doi=10.1666/0094-8373(2005)031[0094:WSSSGA]2.0.CO;2 |issn=0094-8373 |s2cid=44066226|url-access=subscription }}</ref>

The Chengjiang biota has all the animal groups found in the Burgess Shale; however, since it is ten million years older, it more strongly supports the deduction that metazoans diversified earlier or faster in the early Cambrian than does the Burgess Shale fauna alone. The preservation of an extremely diverse faunal assemblage renders the Maotianshan shale the world's most important for understanding the evolution of early multi-cellular life, particularly the members of phylum [[Chordata]], which includes all [[vertebrates]]. The Chengjiang fossils comprise the oldest diverse [[metazoan]] assemblage above the [[Proterozoic]]-[[Phanerozoic]] transition and, thus, the [[fossil record]]'s best data source for understanding the apparently rapid diversification of life known as the [[Cambrian Explosion]].

One of the most intriguing locations of the Chengjiang biota is the Haiyan Lagerstätte, where hundreds of juvenile specimens have been found. This unique location offers insights into the development of most animal groups and as such is a unique deposit in the Cambrian.<ref name=YangEtAl2021>{{cite journal
|journal=Nature Ecology & Evolution
|volume=5
|issue=8
|doi=10.1038/s41559-021-01490-4
|pages=1082–1090
|year=2021|title=A juvenile-rich palaeocommunity of the lower Cambrian Chengjiang biota sheds light on palaeo-boom or palaeo-bust environments
|last1=Yang
|first1=X.
|last2=Kimmig
|first2=J.
|last3=Zhai
|first3=D.
|last4=Liu
|first4=Y.
|last5=Kimmig
|first5=S. R.
|last6=Peng
|first6=S.
|pmid=34183806
|bibcode=2021NatEE...5.1082Y
|s2cid=235674619
}}</ref>

===IUGS geological heritage site===
In respect of 'the Chengjiang fossils represent[ing] an unparalleled record of the fundamentally important rapid diversification of metazoan life in the early Cambrian', the [[International Union of Geological Sciences]] (IUGS) included the 'Cambrian Chengjiang fossil site and lagerstätte' in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022. The organisation defines an 'IUGS Geological Heritage Site' as 'a key place with geological elements and/or processes of international scientific relevance, used as a reference, and/or with a substantial contribution to the development of geological sciences through history.'<ref>{{cite web |title=The First 100 IUGS Geological Heritage Sites |url=https://iugs-geoheritage.org/videos-pdfs/iugs_first_100_book_v2.pdf |archive-url=https://web.archive.org/web/20221027114156/https://iugs-geoheritage.org/videos-pdfs/iugs_first_100_book_v2.pdf |archive-date=2022-10-27 |url-status=live |website=IUGS International Commission on Geoheritage |publisher=IUGS |access-date=13 November 2022}}</ref>

===World Heritage Site===
A {{convert|512|ha|adj=on}} site within this formation, known as the [[Chengjiang Fossil Site]], was listed as a [[World Heritage Site]] by [[UNESCO]] in 2012.<ref name=unescowhs/>

== Preservation and taphonomy ==
[[File:Maotianshania-cylindrica.jpg|thumb|right|''[[Maotianshania|Maotianshania cylindrica]]'', a [[fossil]] [[Nematomorpha|nematomorph worm]], Early [[Cambrian]], Chengjiang Maotianshan Shales]]
{{further|Burgess shale type preservation}}
The fossils occur in a section of mudstone {{convert|50|m|ft}} thick in the [[Yuanshan Member]] of the [[Qiongzhusi Formation]]. The Yuanshan Member is extensive, covering multiple {{convert|10000|km2|sqmi}} of eastern Yunnan Province, where there are many scattered outcrops yielding fossils. Studies of the strata are consistent with a tropical environment with sea level changes and tectonic activity. The region is believed to have been a shallow sea with a muddy bottom. The preserved fauna is primarily [[benthic]] and was likely buried by periodic [[turbidity current]]s, since most fossils do not show evidence of post-mortem transport. Like the younger Burgess Shale fossils, the paleo-environment enabled preservation of non-mineralized, soft body parts. Fossils are found in thin layers less than an inch thick. The soft parts are preserved as aluminosilicate films, often with high oxidized iron content and often exhibiting exquisite details.

The Chengjiang beds are very deeply weathered, as evidenced by their low [[specific gravity]] (i.e., they are very lightweight).<ref name=Gaines2008>{{cite journal
|journal=Geology
|volume=36
|issue=10
|doi=10.1130/G24961A.1
|pages=755–758
|year=2008|title=Cambrian Burgess Shale–type deposits share a common mode of fossilization
|last1=Gaines
|first1=R. R.
|last2=Briggs
|first2=D. E. G.
|last3=Yuanlong
|first3=Z.
|bibcode=2008Geo....36..755G
}}</ref> Trace fossils are abundant.<ref name="Zhang2007">{{Cite journal | doi = 10.1111/j.1365-3121.2007.00765.x | title = Diminutive trace fossils in the Chengjiang Lagerstätte | year = 2007 | last1 = Zhang | first1 = X. G. | last2 = Bergström | first2 = J. | last3 = Bromley | first3 = R. G. | last4 = Hou | first4 = X. G. | journal = Terra Nova | volume = 19 | issue = 6 | pages = 407 | bibcode = 2007TeNov..19..407Z | s2cid = 129833092 }}</ref>

== Chengjiang fauna ==
[[File:Haikouella lanceolata China.jpg|thumb|''[[Haikouella lanceolata]]'', Maotianshan Shales, Chengjiang County, Yunnan Province]]
{{further|Paleobiota of the Maotianshan Shales}}
The Chengjiang biota comprises an extremely diverse faunal assembly, with some 185 species described in the literature as of June 2006. Of these, nearly half are arthropods, few of which had the hard, mineral-reinforced exoskeletons characteristic of all later arthropoda; only about 3% of the organisms known from Chengjiang have hard shells. Most of those are the trilobites (of which there are five species), all of which have been found with traces of legs, antennae, and other soft body parts, an exceedingly rare occurrence in the fossil record. Phylum [[Porifera]] (sponges; 15 species) and [[Priapulida]] (16 species) are also well represented. Other phyla represented are [[Brachiopoda]], [[Chaetognatha]], [[Cnidaria]], [[Ctenophora]], [[Echinodermata]], [[Hyolitha]], [[Nematomorpha]], [[Phoronida]], and [[Chordata]]. Possible [[Mollusca|molluscs]] include ''[[Wiwaxia]]''.<ref>{{Cite journal | doi = 10.1017/S0016756814000648| title = First report of ''Wiwaxia'' from the Cambrian Chengjiang Lagerstätte| journal = [[Geological Magazine]]| pages = 378–382| volume = 152 | issue = 2| year = 2015| last1 = Zhao | first1 = F. C. | last2 = Smith | first2 = M. R. | last3 = Yin | first3 = Z.-J. | last4 = Zeng | first4 = H. | last5 = Hu | first5 = S.-X | last6 = Li | first6 = G.-X. | last7 = Zhu | first7 = M.-Y.| bibcode = 2015GeoM..152..378Z| s2cid = 129654292| url = https://www.repository.cam.ac.uk/bitstream/1810/246363/1/201X-ZHAO-Smith-et-al-Chengjiang-Wiwaxia.pdf }}</ref>

About one in eight animals are problematic forms of uncertain affinity, some of which may have been evolutionary experiments that survived for only a brief period as [[Benthic zone|benthic]] environments rapidly changed in the Cambrian. Chengjiang is the richest source of the [[Lobopodia]], a group including many early [[panarthropod]]s,<ref>{{Cite journal | doi = 10.1038/nature13576 | pmid = 25132546 | journal = [[Nature (journal)|Nature]] | volume = 514 | issue = 7522 | pages = 363–366 | last1 = Smith | first1 = M. R.  | title = Hallucigenia's onychophoran-like claws and the case for Tactopoda | last2 = Ortega Hernández | first2 = J. | url = http://rdcu.be/bKoD| year = 2014 | bibcode = 2014Natur.514..363S | s2cid = 205239797 }}</ref> with six genera represented:  ''[[Luolishania]]'', ''[[Paucipodia]]'', ''[[Cardiodictyon]]'','' [[Hallucigenia]]'' (also known from the Burgess Shale), ''[[Microdictyon]]'', and ''[[Onychodictyon]]''.

Perhaps the most important fossils from Chengjiang are eight possible members of phylum [[Chordata]], the phylum to which all vertebrates belong. The most famous is ''[[Myllokunmingia]]'', possibly a very primitive agnathid (i.e., [[jawless fish]]). Similar to ''Myllokunmingia'' is ''[[Haikouichthys]] ercaicunensis'', another primitive fish-like animal.

A wide range of affinities have been proposed for the enigmatic ''[[Yunnanozoon|Yunnanozoon lividum]]'' including stem [[cephalochordates]], stem or crown [[hemichordates]], [[craniates]], stem [[deuterostomes]], stem [[bilaterians]], or [[ambulacrarians]].<ref>{{cite book|last1=Hou |first1=Xian-guang |last2=Siveter |first2=David J. |last3=Siveter |first3=Derek J. |last4=Aldridge |first4=Richard J. |last5=Cong |first5=Pei-yun |last6=Gabbott |first6=Sarah |last7=Ma |first7=Xiao-ya |last8=Purnell |first8=Mark A. |last9=Williams |first9=Mark |title=The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life |chapter=Bilateria of Uncertain Affinity |edition=2 |date=2017 |pages=264–271 |doi=10.1002/9781118896372.ch25 |isbn=978-1-118-89638-9 }}</ref>  Specimens initially identified as ''Haikouella'' (a genus later deemed a junior synonym of ''Yunnanozoon'')<ref>{{Cite journal |last1=Cong |first1=Pei-Yun |last2=Hou |first2=Xian-Guang |last3=Aldridge |first3=Richard J. |last4=Purnell |first4=Mark A. |last5=Li |first5=Yi-Zhen |date=2015 |editor-last=Smith |editor-first=Andrew |title=New data on the palaeobiology of the enigmatic yunnanozoans from the Chengjiang Biota, Lower Cambrian, China |journal=Palaeontology |language=en |volume=58 |issue=1 |pages=45–70 |doi=10.1111/pala.12117|bibcode=2015Palgy..58...45C |s2cid=84567733 |doi-access=free }}</ref> display has several chordate features, including a discernible heart, dorsal and ventral aorta, gill filaments, and a [[notochord]] (neural chord).<ref>{{Cite journal |last1=Chen |first1=Jun-Yuan |last2=Huang |first2=Di-Ying |last3=Li |first3=Chia-Wei |date=December 1999 |title=An early Cambrian craniate-like chordate |url=https://www.nature.com/articles/990080 |journal=Nature |language=en |volume=402 |issue=6761 |pages=518–522 |doi=10.1038/990080 |bibcode=1999Natur.402..518C |issn=0028-0836|url-access=subscription }}</ref>  A 2024 study placed ''Yunnanozoon'' along the chordate stem.<ref name=Mussini2024>{{cite journal |last1=Mussini |first1=G. |last2=Smith |first2=M. P. |last3=Vinther |first3=J. |last4=Rahman |first4=I. A. |last5=Murdock |first5=D. J. E. |last6=Harper |first6=D. A. T. |last7=Dunn |first7=F. S. |title=A new interpretation of ''Pikaia'' reveals the origins of the chordate body plan |journal=Current Biology |date=2024 |volume=34 |issue=13 |pages=2980–2989.e2 |doi=10.1016/j.cub.2024.05.026 |doi-access=free |pmid=38866005 |bibcode=2024CBio...34.2980M |hdl=10141/623098 |hdl-access=free }}</ref>

Another much-debated group is the [[Vetulicolia]], starting with the discovery of ''[[Vetulicola]]'' in 1987.  Close Chengjiang relatives of ''Vetulicola'' include ''[[Beidazoon]]'' and the [[Didazoonids]].  ''[[Heteromorphus]]'' is more closely related to ''[[Banffia]]'' from the [[Burgess Shale]], but both it and ''Banffia'' are also considered to be vetulicolians.<ref name=Vetulicolia>{{cite book|last1=Hou |first1=Xian-guang |last2=Siveter |first2=David J. |last3=Siveter |first3=Derek J. |last4=Aldridge |first4=Richard J. |last5=Cong |first5=Pei-yun |last6=Gabbott |first6=Sarah |last7=Ma |first7=Xiao-ya |last8=Purnell |first8=Mark A. |last9=Williams |first9=Mark |title=The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life |chapter=Vetulicolians |edition=2 |date=2017 |pages=272–281 |doi=10.1002/9781118896372.ch25}}</ref> Originally described as crustacean arthropods, the ''Vetulicola'' were later erected as a new phylum of primitive deuterostomes by D.G. Shu.<ref name=":02" />  In recent years, a majority of workers have come to see the vetulicolians as stem chordates,<ref name=Onai2023>{{cite journal|last1=Onai |first1=Takayuki |last2=Aramaki |first2=Toshihiro |last3=Takai |first3=Akira |last4=Kakiguchi |first4=Kisa |last5=Yonemura |first5=Shigenobu |title=Cranial cartilages: Players in the evolution of the cranium during evolution of the chordates in general and of the vertebrates in particular |journal=Evolution and Development |volume=25 |pages=197–208 |year=2023 |issue=3 |doi=10.1111/ede.12433|pmid=36946416 |doi-access=free }}</ref> and a 2024 study placed vetulicolians as a basal chordate [[evolutionary grade]], followed by ''Yunnanozoon''.<ref name=Mussini2024 />  An alternative proposal places vetulicolians as a sister group to tunicates.<ref>{{cite journal|last1=García-Bellido |first1=Diego C. |last2=Lee |first2=Michael S. Y. |last3=Edgecombe |first3=Gregory D. |last4=Jago |first4=James B. |last5=Gehling |first5=James G. |last6=Paterson |first6=John R. |year=2014 |title=A new vetulicolian from Australia and its bearing on the chordate affinities of an enigmatic Cambrian group |journal=BMC Evolutionary Biology |volume=14 |issue=1 |article-number=214 |doi=10.1186/s12862-014-0214-z |pmc=4203957 |pmid=25273382 |bibcode=2014BMCEE..14..214G |doi-access=free }}</ref> Vetulicolians are thought to have been swimmers that either were filter feeders or detritivores.<ref>{{cite journal |last1=Aldridge |first1=Richard J. |last2=Hou |first2=Xian-guang |last3=Siveter |first3=David J. |last4=Siveter |first4=Derek J. |last5=Sarah E. |first5=Gabbott |year=2007 |title=The systematics and phylogenetic relationships of vetulicolians |journal=Palaeontology |volume=50 |issue=1 |pages=131–168 |doi=10.1111/j.1475-4983.2006.00606.x |bibcode=2007Palgy..50..131A |s2cid=85722738}}</ref>

Some two dozen animals from the Chengjiang biota are problematic regarding phylogenetic assignment. Among these, ''<nowiki/>'[[Anomalocaris]]' saron'', the alleged predatory terror of the early Cambrian, was the most famous, although that species is later reclassified to ''[[Houcaris]] saron'' and ''[[Innovatiocaris]] maotianshanensis''. Shu (2006) recently described ''[[Stromatoveris]] psygmoglena'' as a possible [[Bilateria|bilateran]] missing link between [[Ediacaran]] fronds and Cambrian [[ctenophore]]s. ''[[Cambrocornulitus]]'' had a tubicolous shell which probably was biomineralized. It shares some affinities with cornulitids and lophophorates.<ref name='VinnWilsonMotus2013'>{{cite journal
 | doi = 10.1080/11035897.2013.801035
 | title = New tubicolous problematic fossil with some "lophophorate" affinities from the Early Cambrian Chengjiang biota in south China
 | year = 2013
 | author = Xianfeng, Y.
 | author2 = Vinn, O.
 | author3 = Xianguang, H.
 | author4 = Xinglei, T.
 | journal = GFF
 | volume = 135
 | issue = 2
 | pages = 184–190 
 | bibcode = 2013GFF...135..184Y
 | s2cid = 129033570
 | url = https://www.researchgate.net/publication/258180839
 | access-date = 2014-06-11}}</ref>

The Chengjiang biota is believed to have inhabited a delta front environment rich in oxygen, with high sedimentation rates and major fluctuations in salinity being the main environmental stressors.<ref>{{cite journal |last1=Saleh |first1=Farid |last2=Qi |first2=Changshi |last3=Buatois |first3=Luis A. |last4=Mángano |first4=M. Gabriela |last5=Paz |first5=Maximiliano |last6=Vaucher |first6=Romain |last7=Zheng |first7=Quanfeng |last8=Hou |first8=Xian-Guang |last9=Gabbott |first9=Sarah E. |last10=Ma |first10=Xiaoya |date=23 March 2022 |title=The Chengjiang Biota inhabited a deltaic environment |journal=[[Nature Communications]] |volume=13 |issue=1 |page=1569 |pmc=8943010 |pmid=35322027 |doi=10.1038/s41467-022-29246-z |bibcode=2022NatCo..13.1569S }}</ref>

== Guanshan biota ==
{{further|List of Guanshan Biota species}}
Located in the Yunnan Province of South China and hosted in the geologically distinct [[Cambrian Stage 4]] [[Wulongqing Formation]], The Guanshan biota are also Burgess shale-type fossils but slightly younger than the Chengjian biota  with an age dating to 515–510 [[Myr]].<ref>{{Cite journal |last1=Chen |first1=Feiyang |last2=Zhang |first2=Zhifei |last3=Betts |first3=Marissa J. |last4=Zhang |first4=Zhiliang |last5=Liu |first5=Fan |date=2019 |title=First report on Guanshan Biota (Cambrian Stage 4) at the stratotype area of Wulongqing Formation in Malong County, Eastern Yunnan, China |journal=Geoscience Frontiers |language=en |volume=10 |issue=4 |pages=1459–1476 |doi=10.1016/j.gsf.2018.09.010|bibcode=2019GeoFr..10.1459C |s2cid=134921385 |doi-access=free }}</ref><ref name=":0">{{Cite journal |last1=Zhao |first1=Jun |last2=Li |first2=Yujing |last3=Selden |first3=Paul A. |last4=Cong |first4=Peiyun |date=2020 |title=New occurrence of the Guanshan Lagerstätte (Cambrian Series 2, Stage 4) in the Kunming area, Yunnan, southwest China, with records of new taxa |url=https://www.tandfonline.com/doi/full/10.1080/03115518.2020.1781257 |journal=Alcheringa: An Australasian Journal of Palaeontology |language=en |volume=44 |issue=3 |pages=343–355 |doi=10.1080/03115518.2020.1781257 |bibcode=2020Alch...44..343Z |s2cid=221093834 |issn=0311-5518 |access-date=2023-03-18 |archive-date=2023-03-18 |archive-url=https://web.archive.org/web/20230318052728/https://www.tandfonline.com/doi/full/10.1080/03115518.2020.1781257 |url-status=live |url-access=subscription }}</ref> Brachiopods are the most abundant species,<ref>{{Cite journal |last1=Hu |first1=Shixue |last2=Zhang |first2=Zhifei |last3=Holmer |first3=Lars E. |last4=Skovsted |first4=Christian B. |date=2010 |title=Soft-Part Preservation in a Linguliform Brachiopod from the Lower Cambrian Wulongqing Formation (Guanshan Fauna) of Yunnan, South China |url=http://www.app.pan.pl/article/item/app20091106.html |journal=Acta Palaeontologica Polonica |language=en |volume=55 |issue=3 |pages=495–505 |doi=10.4202/app.2009.1106 |s2cid=59439966 |issn=0567-7920 |access-date=2023-03-18 |archive-date=2023-03-18 |archive-url=https://web.archive.org/web/20230318052734/https://www.app.pan.pl/article/item/app20091106.html |url-status=live }}</ref> followed by trilobites. Other species belong to sponges, chancelloriids, cnidarians, ctenophores, priapulids, lobopodians, arthropods, anomalocaridids, hyoliths, molluscs, brachiopods, echinoderms, algae and vetulicolians. There are also the earliest-known eocrinoids, unidentified soft-bodied animals and abundant trace fossils.<ref name=":1">{{Cite journal |last1=Hu |first1=ShiXue |last2=Zhu |first2=MaoYan |last3=Steiner |first3=Michael |last4=Luo |first4=HuiLin |last5=Zhao |first5=FangChen |last6=Liu |first6=Qi |date=2010 |title=Biodiversity and taphonomy of the Early Cambrian Guanshan biota, eastern Yunnan |url=http://link.springer.com/10.1007/s11430-010-4086-9 |journal=Science China Earth Sciences |language=en |volume=53 |issue=12 |pages=1765–1773 |doi=10.1007/s11430-010-4086-9 |bibcode=2010ScChD..53.1765H |s2cid=128882075 |issn=1674-7313|url-access=subscription }}</ref>

The Guanshan biota are regarded as successors of the Chengjian biota,<ref name=":0" /> and share many species. The unique species include arthropods like ''[[Guangweicaris]]''<ref>{{Cite journal |last1=Wu |first1=Yichen |last2=Liu |first2=Jianni |date=2019 |title=Anatomy and relationships of the fuxianhuiid euarthropod Guangweicaris from the early Cambrian Guanshan Biota in Kunming, Yunnan, Southwest China revisited |url=http://www.app.pan.pl/article/item/app005422018.html |journal=Acta Palaeontologica Polonica |volume=64 |doi=10.4202/app.00542.2018 |s2cid=201291723 |doi-access=free |access-date=2023-03-18 |archive-date=2023-03-18 |archive-url=https://web.archive.org/web/20230318054121/https://www.app.pan.pl/article/item/app005422018.html |url-status=live }}</ref> and ''[[Astutuscaris]],''<ref>{{Cite journal |last1=Jiao |first1=De guang |last2=Du |first2=Kunsheng |date=2022 |title=A new euarthropod from the Cambrian Stage 4 Guanshan Biota of South China |url=https://www.app.pan.pl/article/item/app009372021.html |journal=Acta Palaeontologica Polonica |volume=67 |doi=10.4202/app.00937.2021 |s2cid=253068676 |doi-access=free |access-date=2023-03-18 |archive-date=2023-03-18 |archive-url=https://web.archive.org/web/20230318054119/https://www.app.pan.pl/article/item/app009372021.html |url-status=live }}</ref>alongside vetulicolians like ''[[Vetulicola gantoucunensis]]''<ref>{{Cite journal |last1=Huilin |first1=Luo |last2=Xiaoping |first2=Fu |last3=Shixue |first3=Hu |last4=Yong |first4=Li |last5=Liangzhong |first5=Chen |last6=Ting |first6=You |last7=Qi |first7=Liu |date=2005 |title=New Vetulicoliids from the Lower Cambrian Guanshan Fauna, Kunming |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1755-6724.2005.tb00860.x |journal=Acta Geologica Sinica - English Edition |language=en |volume=79 |issue=1 |pages=1–6 |doi=10.1111/j.1755-6724.2005.tb00860.x |bibcode=2005AcGlS..79....1L |s2cid=129031316 |access-date=2023-03-18 |archive-date=2023-03-08 |archive-url=https://web.archive.org/web/20230308053427/https://onlinelibrary.wiley.com/doi/10.1111/j.1755-6724.2005.tb00860.x |url-status=live |url-access=subscription }}</ref> and ''[[Vetulicola longbaoshanensis|V. longbaoshanensis]]''.<ref>{{Cite journal |last1=Li |first1=JinShu |last2=Liu |first2=JianNi |last3=Ou |first3=Qiang |date=2017 |title=New observations on Vetulicola longbaoshanensis from the Lower Cambrian Guanshan Biota (Series 2, Stage 4), South China |url=http://link.springer.com/10.1007/s11430-017-9088-y |journal=Science China Earth Sciences |language=en |volume=60 |issue=10 |pages=1795–1804 |doi=10.1007/s11430-017-9088-y |bibcode=2017ScChD..60.1795L |s2cid=135037211 |issn=1674-7313|url-access=subscription }}</ref>

== Gallery ==
<gallery>
File:Misszhouia longicaudata 2.jpg|''[[Misszhouia]] longicaudata''
File:Heliomedusa orienta.jpg|''[[Heliomedusa]] orienta''
File:Leanchoilia illecebrosa.jpg|''[[Leanchoilia]] illecebrosa''
</gallery>

== See also ==
* [[Geography of China]]
* [[Stephen Jay Gould]], ''[[Wonderful Life (book)|Wonderful Life]]''
* [[List of arthropods of the Cambrian Period]]
* [[List of Xiaoshiba Biota species]]

== References ==
{{Reflist}}

== Further reading ==<!-- ActaGeolSin81:1. -->
* {{cite journal | last1 = Conway-Morris | first1 = S. | year = 2003 | title = The Cambrian "explosion" of metazoans and molecular biology: would Darwin be satisfied? | journal = Int J Dev Biol | volume = 47 | issue = 7–8| pages = 505–515 | pmid = 14756326 }}
* [http://www.fossilmuseum.net/Fossil_Sites/Chengjiang.htm Fossils of the Chengjiang Maotianshan Shale] - URL retrieved September 20, 2006
* Hou, Xian-Guang; Aldridge, Richard J., Bengstrom, Jan; [[David J. Siveter|Siveter, David J.]] ;Feng, Xiang-Hong 2004; The Cambrian Fossils of Chengjang, China, Blackwell Science Ltd, 233 pp.
* [http://palaeo.gly.bris.ac.uk/Palaeofiles/Lagerstatten/chngjang/ Preservation, Taphonomy and Palaeoecology of the Chengjiang Biota] - URL retrieved September 20, 2006
* {{cite journal | last1 = Shu | first1 = D-G | last2 = Luo | first2 = H-L | last3 = Conway Morris | first3 = S. | last4 = Zhang | first4 = X-L | last5 = Hu | first5 = S-X | last6 = Chen | first6 = L. | last7 = Han | first7 = J. | last8 = Zhu | first8 = M. | last9 = Li | first9 = Y | year = 1999 | title = Lower Cambrian Vertebrates from South China | journal = Nature | volume = 402 | issue = 6757| pages = 42–46  | display-authors = etal  | doi = 10.1038/46965| bibcode = 1999Natur.402...42S | s2cid = 4402854 }}
* {{cite journal | last1 = Shu | first1 = D. G. | last2 = Conway Morris | first2 = S. | last3 = Han | first3 = J. | last4 = Chen | first4 = L. | last5 = Zhang | first5 = X. L. | last6 = Zhang | first6 = Z. F. | year = 2001 | title = Primitive deuterostomes from the Chengjiang Lagerstatte (Lower Cambrian, China) | journal = Nature | volume = 414 | issue = 6862| pages = 419–424 | doi=10.1038/35106514| pmid = 11719797 | display-authors = 6 | bibcode = 2001Natur.414..419S | last7 = Li | first7 = Y. | last8 = Liu | first8 = J.-N. | s2cid = 4345484 }}
* {{cite journal | last1 = Shu | first1 = D. | last2 = Conway Morris | first2 = S. | last3 = Zhang | first3 = Z. F. | last4 = Liu | first4 = J. N. | last5 = Han | first5 = J. | last6 = Chen | first6 = L.| year = 2003 | title = A new species of yunnanozoan with implications for deuterostome evolution | journal = Science | volume = 299 | issue = 5611| pages = 1380–1384 | doi=10.1126/science.1079846| pmid = 12610301  | s2cid = 45702564 | display-authors = etal  }}
* {{cite journal | last1 = Shu | first1 = D. G. | last2 = Conway Morris | first2 = S. | last3 = Han | first3 = J. | last4 = Zhang | first4 = Z. F. | last5 = Liu | first5 = J. N. | year = 2004 | title = Ancestral echinoderms from the Chengjiang deposits of China | journal = Nature | volume = 430 | issue = 6998| pages = 422–428 | pmid = 15269760 | doi=10.1038/nature02648| bibcode = 2004Natur.430..422S | s2cid = 4421182 }}
* {{cite journal | last1 = Shu | first1 = D. G. | last2 = Conway Morris | first2 = S. | last3 = Han | first3 = J. | last4 = Li | first4 = Y. | last5 = Zhang | first5 = X. L. | last6 = Hua | first6 = H. | year = 2006 | title = Lower Cambrian vendobionts from China and early diploblast evolution | journal = Science | volume = 312 | issue = 5774| pages = 731–734 | doi=10.1126/science.1124565| pmid = 16675697 | display-authors = 6 | bibcode = 2006Sci...312..731S | last7 = Liu | first7 = J.-N. | last8 = Guo | first8 = J.-F. | last9 = Yao | first9 = Y. | last10 = Yasui | first10 = K. | s2cid = 1235914 }}
* {{cite journal | last1 = Waloszek | first1 = D. | last2 = Maas | first2 = A. | year = 2005 | title = The evolutionary history of crustacean segmentation: a fossil-based perspective | journal = Evol Dev | volume = 7 | issue = 6| pages = 515–527 | doi=10.1111/j.1525-142x.2005.05056.x| pmid = 16336406 | s2cid = 27327765 }}
* {{cite journal | last1 = Xian-guang | first1 = H. | last2 = Aldridge | first2 = R. J. | last3 = Siveter | first3 = D. J. | last4 = Xiang-hong | first4 = F. | year = 2002 | title = New evidence on the anatomy and phylogeny of the earliest vertebrates | journal = Proc Biol Sci | volume = 269 | issue = 1503| pages = 1865–1869 | doi=10.1098/rspb.2002.2104| pmid = 12350247 | pmc=1691108}}
* {{cite journal | last1 = Zhang | first1 = X. | last2 = Han | first2 = J. | last3 = Zhang | first3 = Z. | last4 = Liu | first4 = H. | last5 = Shu | first5 = D. | year = 2003 | title = Reconsideration of the supposed naraoiid larva from the Early Cambrian Chengjiang Lagerstätte, South China | journal = Palaeontology | volume = 46 | issue = 3| pages = 447–66 | doi=10.1111/1475-4983.00307| bibcode = 2003Palgy..46..447Z | doi-access = free }}
* {{cite journal | last1 = Zhang | first1 = X. G. | last2 = Hou | first2 = X. G. | year = 2004 | title = Evidence for a single median fin-fold and tail in the Lower Cambrian vertebrate, Haikouichthys ercaicunensis | journal = J Evol Biol | volume = 17 | issue = 5| pages = 1162–1166 | doi=10.1111/j.1420-9101.2004.00741.x| pmid = 15312089 | doi-access = free }}

== External links ==
* {{cite web |url=http://www.uni-wuerzburg.de/palaeontologie/Stuff/casu30.htm |title=Chengjiang |access-date=2005-11-22 |url-status=dead |archive-url=https://web.archive.org/web/20051024105322/http://www.uni-wuerzburg.de/palaeontologie/Stuff/casu30.htm |archive-date=2005-10-24 }}
* [http://www.fossilmuseum.net/Fossil_Sites/Chengjiang/Chengjiang-Biota.htm Chengjiang Biota] at fossilmuseum.net

{{Cambrian footer}}
{{Burgess Shale type preservation}}

[[Category:Geologic formations of China]]
[[Category:Cambrian System of Asia]]
[[Category:Cambrian China]]
[[Category:Shale formations]]
[[Category:Cambrian northern paleotemperate deposits]]
[[Category:Lagerstätten]]
[[Category:Paleontology in Yunnan]]
[[Category:Maotianshan shales fossils| ]]
[[Category:Geography of Yuxi]]
[[Category:First 100 IUGS Geological Heritage Sites]]