Table Of ContentEdiacaran microfossils from the
Doushantuo Formation chert nodules in the
Yangtze Gorges area, South China, and
new biozones
by
Pengju Liu and Małgorzata Moczydłowska
Acknowledgements
Financial support for the publication of this issue of Fossils and Strata
was provided by the Lethaia Foundation
Contents
Ediacaran microfossils from the Doushantuo Formation chert Asterocapsoides fluctuensis n. sp. . . . . . . . . . . . . . . . . . . . . . 68
nodules in the Yangtze Gorges area, South China, and new Genus Bacatisphaera Zhou, Brasier & Xue, 2001, emend.
biozones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Xiao, Zhou, Liu, Wang & Yuan, 2014 . . . . . . . . . . . . . . . . . . 68
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Bacatisphaera sparga n. sp. . . . . . . . . . . . . . . . . . . . . . . . . . 68
Geological setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Genus Briareus Knoll, 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
General regional geology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Briareus borealis Knoll, 1992 . . . . . . . . . . . . . . . . . . . . . . . . 71
Th e Doushantuo Formation lithostratigraphy . . . . . . . . . . . . . . 4 Briareus robustus n. sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Depositional environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Briareus vasformis n. sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Age of the Doushantuo Formation . . . . . . . . . . . . . . . . . . . . . . . . 6 Genus Calyxia Willman, 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Calyxia xandaros Willman, 2008 . . . . . . . . . . . . . . . . . . . . 75
Repository . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Genus Cavaspina Moczydłowska, Vidal & Rudavskaya,
Studied geological successions . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Th e Baiguoyuan section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Cavaspina acuminata (Kolosova, 1991) Moczydłowska,
Th e Jiuqunao section (= Jijiawan) . . . . . . . . . . . . . . . . . . . . . . . . 14 Vidal & Rudavskaya, 1993 . . . . . . . . . . . . . . . . . . . . . . . . 76
Th e Jiulongwan composite section . . . . . . . . . . . . . . . . . . . . . . . 19 Cavaspina basiconica Moczydłowska, Vidal & Rudavskaya,
Th e Chenjiayuanzi section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Th e Nantuocun section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Cavaspina conica n. sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Th e Wangfenggang section (= Liantuo) . . . . . . . . . . . . . . . . . . 24 Genus Cymatiosphaeroides Knoll, 1984, emend. Knoll,
Th e Niuping composite section. . . . . . . . . . . . . . . . . . . . . . . . . . 25 Swett & Mark, 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Th e northern Xiaofenghe section . . . . . . . . . . . . . . . . . . . . . . . . 27 Cymatiosphaeroides forabilatus n. sp. . . . . . . . . . . . . . . . . 81
Th e southern Xiaofenghe section . . . . . . . . . . . . . . . . . . . . . . . . 29 Cymatiosphaeroides kullingii Knoll, 1984, emend.
Th e Dishuiyan section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Butterfi eld, Knoll & Swett, 1994 . . . . . . . . . . . . . . . . . . . 84
Th e Liuhuiwan section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Genus Dicrospinasphaera Yuan & Hofmann, 1998,
Biostratigraphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 emend. Yin, Wang, Yuan & Zhou, 2011, emended . . . . . . . 86
General comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Dicrospinasphaera improcera n. sp. . . . . . . . . . . . . . . . . . . 87
Th e Doushantuo Formation biostratigraphy . . . . . . . . . . . . . . 32 Dicrospinasphaera zhangii Yuan & Hofmann,
Species recorded in member II . . . . . . . . . . . . . . . . . . . . . 33 1998, emend. Yin, Wang, Yuan & Zhou, 2011,
Concurrent species in members II and III . . . . . . . . . . . . 34 emended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Species restricted to member III . . . . . . . . . . . . . . . . . . . . 35 Genus Distosphaera Zhang, Yin, Xiao & Knoll, 1998,
Establishing stratigraphic ranges of selected species . . . . . . . . 36 emended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
New biozones in the Doushantuo Formation . . . . . . . . . . . . . . 40 Distosphaera? corniculata n. sp. . . . . . . . . . . . . . . . . . . . . . 91
Appendisphaera grandis–Weissiella grandistella– Distosphaera speciosa Zhang, Yin, Xiao & Knoll, 1998,
Tianzhushania spinosa Assemblage Zone . . . . . . . . . . . 41 emended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Tanarium tuberosum–Schizofusa zangwenlongii Genus Eotylotopalla Yin, 1987 . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Assemblage Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Eotylotopalla dactylos Zhang, Y., Yin L., Xiao & Knoll,
Tanarium conoideum–Cavaspina basiconica 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Assemblage Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Eotylotopalla delicata Yin, L., 1987 . . . . . . . . . . . . . . . . . . 96
Tanarium pycnacanthum–Ceratosphaeridium Eotylotopalla quadrata n. sp. . . . . . . . . . . . . . . . . . . . . . . . 97
glaberosum Assemblage Zone . . . . . . . . . . . . . . . . . . . . . . 41 Eotylotopalla strobilata (Faizullin, 1998) Sergeev, Knoll &
Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Vorobeva, 2011 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Systematic palaeontology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Genus Ericiasphaera Vidal, 1990, emend. Grey, 2005 . . . . . . . 99
Genus Alicesphaeridium Zang in Zang & Walter, 1992, Ericiasphaera fibrilla n. sp. . . . . . . . . . . . . . . . . . . . . . . . .101
emend. Grey, 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Ericiasphaera magna (Zhang, 1984) Zhang, Yin L., Xiao
Alicesphaeridium medusoidum Zang in Zang & & Knoll, 1988 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
Walter, 1992, emend. Grey, 2005 . . . . . . . . . . . . . . . . . . 43 Ericiasphaera rigida Zhang, Yin, Xiao & Knoll, 1998 . .104
Genus Ancorosphaeridium Sergeev, Knoll & Genus Estrella n. gen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104
Vorobeva, 2011, emend. Moczydłowska & Estrella greyae n. sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
Nagovitsin, 2012, emend. Moczydłowska, 2015 . . . . . . . . . 46 Estrella recta n. sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108
Ancorosphaeridium magnum Sergeev, Knoll & Estrella sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108
Vorobeva, 2011, emend. Moczydłowska & Genus Gyalosphaeridium Zang in Zang & Walter, 1992,
Nagovitsin, 2012, emend. Moczydłowska, 2015 . . . . . 46 emend. Grey 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108
Genus Appendisphaera Moczydłowska, Vidal & Gyalosphaeridium pulchrum Zang in Zang & Walter,
Rudavskaya, 1993, emend. Moczydłowska, 2005 . . . . . . . . 47 1992, emend. Grey 2005 . . . . . . . . . . . . . . . . . . . . . . . .111
Appendisphaera clustera n. sp. . . . . . . . . . . . . . . . . . . . . . . 47 Genus Hocosphaeridium Zang in Zang & Walter, 1992
A ppendisphaera grandis Moczydłowska, Vidal & emend. Xiao, Zhou, Liu, Wang & Yuan, 2014 . . . . . . . . . .112
Rudavskaya, 1993, emend. Moczydłowska, 2005 . . . . . 48 Hocosphaeridium anozos (Willman, 2008) Xiao, Zhou,
A ppendisphaera lemniscata n. sp. . . . . . . . . . . . . . . . . . . . 54 Liu, Wang & Yuan, 2014 . . . . . . . . . . . . . . . . . . . . . . . .113
Appendisphaera longispina Liu, Xiao, Yin, Chen, Genus Knollisphaeridium Willman & Moczydłowska,
Zhou & Li, 2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 2008, emended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115
Appendisphaera longitubulare (Liu, Xiao, Yin, Chen, Knollisphaeridium bifurcatum Xiao, Zhou, Liu, Wang &
Zhou & Li, 2014) n. comb. . . . . . . . . . . . . . . . . . . . . . . . 55 Yuan, 2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115
Appendisphaera setosa Liu, Xiao, Yin, Chen, Zhou Knollisphaeridium coniformum n. sp. . . . . . . . . . . . . . . .115
& Li, 2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Knollisphaeridium heliacum n. sp. . . . . . . . . . . . . . . . . . .118
Appendisphaera tabifica Moczydłowska, Vidal Knollisphaeridium maximum (Yin, L., 1987) Willman &
& Rudavskaya, 1993, emended . . . . . . . . . . . . . . . . . . . . . 58 Moczydłowska, 2008, emended . . . . . . . . . . . . . . . . . .118
Appendisphaera tenuis Moczydłowska, Vidal & Genus Laminasphaera n. gen. . . . . . . . . . . . . . . . . . . . . . . . . .123
Rudavskaya, 1993, emend. Moczydłowska, 2005 . . . . . 61 Laminasphaera capillata n. sp. . . . . . . . . . . . . . . . . . . . . .124
Genus Asseserium Nagovitsin & Moczydłowska, 2012 . . . . .65 Genus Membranosphaera n. gen. . . . . . . . . . . . . . . . . . . . . . .124
Asseserium diversum Nagovitsin & Moczydłowska, Membranosphaera formosa n. sp. . . . . . . . . . . . . . . . . . .127
2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Genus Mengeosphaera Xiao, Zhou, Liu, Wang &
Asseserium fusulentum Nagovitsin & Moczydłowska, Yuan, 2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127
2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Mengeosphaera chadianensis (Chen & Liu, 1986) Xiao,
Genus Asterocapsoides Yin L. & Li, 1978, emend. Xiao, Zhou, Liu, Wang & Yuan, 2014 . . . . . . . . . . . . . . . . . . .129
Zhou, Liu, Wang & Yuan, 2014 . . . . . . . . . . . . . . . . . . . . . . . 66 Mengeosphaera flammelata n. sp. . . . . . . . . . . . . . . . . . .132
Mengeosphaera gracilis Liu, Xiao, Yin, Chen, Zhou & Li, Tanarium muntense Grey, 2005 . . . . . . . . . . . . . . . . . . . .147
2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132 Tanarium paucispinosum Grey, 2005. . . . . . . . . . . . . . . .149
Mengeosphaera latibasis Liu, Xiao, Yin, Chen, Zhou Tanarium pilosiusculum Vorobeva, Sergeev &
& Li, 2014, emended . . . . . . . . . . . . . . . . . . . . . . . . . . . .133 Knoll, 2009 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .151
Mengeosphaera lunula n. sp. . . . . . . . . . . . . . . . . . . . . . . .136 Tanarium triangularis (Liu, Xiao, Yin, Chen, Zhou &
Mengeosphaera cf. M. stegosauriformis . . . . . . . . . . . . . .136 Li, 2014) new combination . . . . . . . . . . . . . . . . . . . . . .151
Genus Multifronsphaeridium Zang in Zang & Tanarium tuberosum Moczydłowska, Vidal &
Walter, 1992, emend. Grey, 2005 . . . . . . . . . . . . . . . . . . . . .137 Rudavskaya, 1993, emend. Moczydłowska, 2015. . . .153
Multifronsphaeridium pelorium Zang in Zang & Walter, Tanarium uniformum n. sp. . . . . . . . . . . . . . . . . . . . . . . .156
1992, emend. Grey, 2005 . . . . . . . . . . . . . . . . . . . . . . . .138 Genus Variomargosphaeridium Zang in Zang & Walter,
Multifronsphaeridium ramosum Nagovitsin & 1992 emend. Xiao, Zhou, Liu, Wang & Yuan, 2014 . . . . .158
Moczydłowska in Moczydłowska & Nagovitsin, Variomargosphaeridium litoschum Zang in Zang &
2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140 Walter, 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158
Genus Sinosphaera Zhang, Yin, Xiao & Knoll, 1998 Variomargosphaeridium varietatum n. sp. . . . . . . . . . . .160
emend. Xiao, Zhou, Liu, Wang & Yuan, 2014 . . . . . . . . . .140 Genus Verrcosphaera n. gen. . . . . . . . . . . . . . . . . . . . . . . . . . .160
Sinosphaera speciosa (Zhou, Brasier & Xue, 2001) Verrucosphaera minima n. sp. . . . . . . . . . . . . . . . . . . . . .160
Xiao, Zhou, Liu, Wang & Yuan, 2014 . . . . . . . . . . . . .140 Genus Weissiella Vorobeva, Sergeev & Knoll, 2009,
Genus Tanarium Kolosova, 1991 emend. emended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162
Moczydłowska, Vidal & Rudavskaya, 1993 . . . . . . . . . . . .143 Weissiella grandistella Vorobeva, Sergeev & Knoll,
Tanarium capitatum n. sp. . . . . . . . . . . . . . . . . . . . . . . . .143 2009, emended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163
Tanarium cuspidatum Liu, Xiao, Yin, Chen, Zhou & Li, Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .166
2014, comb. nov., emended . . . . . . . . . . . . . . . . . . . . . .145 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .167
Tanarium minimum Liu, Xiao, Yin, Chen, Zhou & Li,
2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147
Ediacaran microfossils from the Doushantuo Formation chert
nodules in the Yangtze Gorges area, South China, and new
biozones
PENGJULIUANDMAŁGORZATAMOCZYDŁOWSKA
Liu, P. & Moczydłowska, M. 2019: Ediacaran microfossils from the Doushantuo
FormationchertnodulesintheYangtzeGorgesarea,SouthChina,andnewbiozones.
FossilsandStrata,No.65,pp.1–172.
ThenewgeologicalsurveyoftheEdiacaranDoushantuoFormationandmicropalaeon-
tologicalstudieshaveyieldedamuchlargerandmorediverseassociationoforganic‐
walled microfossils than previously reported. Over 100 species recovered from chert
noduleshavenowbeenidentified,including24newspecies.Themicrofossiltaxonomy
hasbeenrevisedaccordingly,addingtotheappreciationofbiodiversity,globaldistribu-
tionandbiostratigraphicsignificance.Thespeciesrangeshavebeenscrutinizedandthe
firstandlastappearancedatumhavebeenestablishedforseveralworldwidedistributed
speciesthatareusedforproposednewassemblagezonesintheYangtzeGorgesarea,
andpotentiallyforglobalsubdivisionoftheEdiacaranSystem.Theseare,inascending
stratigraphicorder,theAppendisphaeragrandis–Weissiellagrandistella–Tianzhushania
spinosa,Tanariumtuberosum–Schizofusazangwenlongii,Tanariumconoideum–Cavas-
pinabasiconicaandTanariumpycnacanthum–CeratosphaeridiumglaberosumAssem-
blageZones.Thesuccessivezones’lowerboundariesareestimatedat633,620,610and
shortlyafter580Matimehorizons.ThegeologicalreviewoftheDoushantuoForma-
tionandnewobservationsofelevensuccessionsinanattempttodiscernunconformi-
ties and stratigraphic hiati have recognized the relative time relationships between
dismemberedsuccessionsandhaveupdatedthespeciesranges.TheDoushantuoFor-
mationissedimentologicallydiscontinuous,partiallycondensedandcomprisesseveral
un‐andparaconformitiesinvolvinghiatiofunknownduration.Therefore,thespecies
andzoneranges,withtheexceptionofthetwobasalzonesthatarebracketedbyiso-
topic datings, are approximate. The biotic radiations documented by microfossil
appearanceandtheoriginofnewspeciesattheverybeginningoftheEdiacaranPeriod
at633Ma,followedexponentiallythroughtheintervalupto565Ma(ca.68Ma)are
innovativeevolutionary events.Ediacaran microbiotaphylogeneticaffiliationsarenot
fullyresolvedandassumedtobeamongauto‐andheterotrophicprotistsorevenmeta-
zoans.Manytaxaarealgalinorigin,includingthosestudiedhere.Biologicalaffinities
ofmicrofossilsremainamongthemostintriguingproblemsintheevolutionoflifeat
thattime. □ Acritarchs,Ediacaranbiozones,Ediacaranradiations,phytoplankton,tax-
onomy.
Pengju Liu [[email protected]], Institute of Geology, Chinese Academy of Geological
Sciences, Beijing 100037, China; Małgorzata Moczydłowska [[email protected]],
DepartmentofEarthSciences,Palaeobiology,UppsalaUniversity,Villavägen16SE752
36Uppsala,Sweden;manuscriptreceivedon2/11/2017;manuscriptacceptedon10/07/
2018.
Introduction
modernworld.Therecoveryofmarinebasinsandcli-
matic rebound after the Cryogenian ice ages, global
The evolutionary history of the biosphere is intrinsi- warming, epicontinental transgressions and increased
cally bound up with global environmental change nutrient input formed ecosystems in which bacteria,
from the primary formation of habitable conditions, protists and multicellular eukaryotes, including
increasing oxygenation through the Proterozoic Eon emerging metazoans, rapidly evolved (Jenkins et al.
thatmadetheEarthmoresuitablefororganismswith 2004;Grey2005;Narbonne2005;Canfieldet al.2007;
complex metabolic processes and higher aerobic Grotzinger et al. 2011; Hoffman et al. 2017). These
requirements,leadingfinallytoageosystemthatcould codependent relationships between the Ediacaran
sustainanimals.TheterminalProterozoicanditsEdi- environmental and biotic systems are elegantly
acaran Period is a unique example of both environ- recordedbythewealthoforganismallineagesanddis-
mental and biotic transformations leading to the cretetaxainthenewlyemergentmarineniches.
DOI10.1002/9781119564195©2019LethaiaFoundation.PublishedbyJohnWiley&SonsLtd
2 P.Liu&M.Moczydłowska FOSSILSANDSTRATA
The exponential diversification of unicellular, theobjectiveofrevealingtheappearancesandearliest
organic‐walled microbes revealed in the number of ranges of microfossil species for biostratigraphic
newspecies,theirmorphologicdisparityandthenar- application; testing the current biozones; and estab-
row time frame in which they appear, is well docu- lishing new, refined biozones. The findings extend
mented in the Ediacaran successions. Their number the known occurrence of many species, document
exceeds 100 described form‐species with worldwide numerouspreviouslyunknownspeciesbasedonnew
distribution, of which some are endemic. The best material and revised taxonomy and include an
knownofthembymorphologiccomplexityandvari- attempt to formulate biozones suitable for the regio-
able preservation modes (organically preserved or nalandglobalbiostratigraphyandtheEdiacaranSys-
permineralized) are microfossil assemblages from temsubdivision.
central and southernAustralia, theSiberian and East
European platforms, and South China. Their discov- Geological setting
eryandtheearlysearchfordiversityandphylogenetic
affinities (Timofeev 1969; Zhang 1981a, b; Yin 1985;
General regional geology
Zang & Walter 1989, 1992a, b; Moczydłowska et al.
1993;Yuan&Hofmann1998;Zhanget al.1998a,b), In a tectonic framework, the South China crustal
and subsequent comprehensive studies (Grey 2005; block constitutes a major terrane of the present‐day
Vorobeva et al. 2007, 2009a; Willman & Moczy- continent. It was amalgamated about 1 Ga into a
dłowska 2008, 2011; Sergeev et al. 2011; Moczy- stable Proterozoic craton, including some Archaean
dłowska & Nagovitsin 2012; Liu et al. 2014a, b; Xiao 2.8 Ga basement, and subsequently covered by sedi-
et al.2014a),changedtheconceptofPrecambrianlife mentary successions of the Neoproterozoic and
alongside the famous Ediacara‐type biota and early younger ages (Li et al. 2003; Wang & Li 2003; Tors-
metazoans (Glaessner 1984; Narbonne 2005; Fedon- vik & Cocks 2017). The Neoproterozoic sedimentary
kinet al.2007;Vickers‐Rich&Komarower2007). cover that overlies the Yangtze block consists of the
The Ediacaran environmental and biotic develop- twoCryogenianglaciogenicdiamictitesandinterven-
ment is an affirming model for the theory of evolu- ing interglacial shale/siltstone/sandstone strata and
tion by natural selection some 150 years after its the Ediacaran marine carbonate and siliciclastic
formulationbyDarwin(1859). deposits that extend over a large area of the Yangtze
The Ediacaran successions in the Yangtze Gorges Platform (Zhou et al. 2004; Jiang et al. 2006, 2011;
area,partoftheYangtzePlatforminSouthChina,are DobrzinskiandBahlburg2007;Fig. 1A,B).
comprised of carbonate and siliciclastic sedimentary The Ediacaran successions on the Yangtze
rocksaccumulatedinshallowtomorebasinalmarine Platformreachatotalcumulativethicknessofca.400–
depositionalconditions(Jianget al.2011).Theyhave 900 m(Xinget al.1996)orca.250–1000 m(Jianget
been intensively studied because of the yield of a al.2011)andaccumulatedinshallowmarinetobasi-
diverse early biota that is highly significant from an naldepositionalsettings(Zhuet al.2003,2013;Jiang
evolutionary point of view. The lower Ediacaran et al. 2006, 2011; Zhou & Xiao 2007). They are well
DoushantuoFormationinSouthChinaisoverlainby exposedacrosstheplatformarea,althoughindifferent
the Dengying/Liuchapo formations and is of major stratigraphicportionsandinvariableverticalandlat-
interestbecauseofitsexceptionalpreservationofdis- eral occurrences that overlie the Nantuo Formation
tinctmicrofossils(forrecentsummaries,seeLiuet al. diamictite(Fig. 2).Thestrataarelargelyun‐deformed,
2014b;Xiaoet al.2014a;Zhouet al.2017awithrefer- other than dipping at a low angle and flexured along
ences). The geochronology of the formation is well the faults. They have been strongly diagenetically
constrainedfrom635to551 Ma(Condonet al.2005) alteredbyhydrothermalsilicification,phosphatization
and provides a time frame for the estimation of the andcarbonatecrystallization,althoughnotmetamor-
rate of speciation and evolution of early biotas. The phosed(Derry2010;Xiaoet al.2010;Derkowskiet al.
Doushantuo succession is a potential candidate for 2013;Hohlet al.2015).TheentireEdiacaransucces-
thesubdivisionoftheEdiacaranSystem(Narbonneet sionisrelativelythinincomparisonwithother glob-
al.2012;Xiaoet al.2016). allydistributedsuccessions.Itishighlycondensedor
We examined eleven sections with exposures of reduced in thickness, sedimentologically discontinu-
the Doushantuo Formation in the Yangtze Gorges ousandcomprisesregionalunconformitiesandstrati-
area (Fig. 1A, B) for organic‐walled microfossils in graphicgapswhoseextentareunknown(Wanget al.
memberII,andincertainintervalsofmemberIII,as 1998;Zhuet al.2003,2007a,b,2013;Grey2005;Xiao
a continuation of the detailed studies carried out by et al.2012;Fig. 2;seebelow).TheEdiacaranstrataare
Liu et al. (2014b) on member III. Our focus was on referredtotheDoushantuoandtheoverlyingDengy-
the lower part of the Doushantuo Formation with ing/Liuchapo formations, which range in thickness
FOSSILSANDSTRATA EdiacaranmicrofossilsfromtheDoushantuoFormation 3
Fig.1. Geologicalsketch‐mapofChinashowingthemajorcrustalblocks(A)andtheHuanglingAnticlineandYangtzeGorgesareawith
locationofstudiedsections(B).Thewhiteframein(A)marksthepositionoftheHuanglingAnticlineinthenorthernYangtzePlatform.
ModifiedafterLiuetal.(2014b).
from 40 to 220 m and 200 to 1000 m, respectively Nantuo and Dengyingformations and dips 7° to 11°
(Zhanget al.2005;Zhouet al.2007;Zhuet al.2007a, (Zhaoet al.1985).
b, 2013; Jiang et al. 2011; Xiao et al. 2012; Liu et al. The formation subdivision into members, called
2014b). Member 1–4, was proposed by Wang et al. (1998),
The Doushantuo Formation is of a major interest who referred to the Tianjiayuanzi type section and
because it contains evolutionarily novel and diverse characterized these in general lithological terms.
fossil assemblages. It has been extensively studied in However, the succession of the nominal type section
various aspects of its litho‐, chemo‐ and biostratigra- has neither been presented (only the ‘representative
phy, facies development and environmental condi- section’ in Miaohe), nor have the member bound-
tions,andgeochronology(Jianget al.2011;Zhuet al. aries indicated in the measured succession levels and
2013; Liu et al. 2014a, b; Xiao et al. 2014a, b; Zhou defined.ThemembersoftheDoushantuoFormation
et al.2017a,b;andreferencesthere).Theformation’s have been followed, but respectively referred to as
geochronology is well‐established within ca. 635– Member 1–4 (Zhu et al. 2003; Lu et al. 2012), mem-
551 Ma (Condon et al. 2005), and while the entire ber 1–4 (Zhou & Xiao 2007), member I–IV (Zhou
time span of the Ediacaran Period is 635–541 Ma et al.2007;McFaddenet al.2008)andMemberI–IV
(Ogget al.2016),itsterminal10 Maisencompassed (Xiao et al. 2010, 2012; Liu et al. 2013, 2014a, b;
ontheYangtzePlatformbytheDengyingFormation Zhou et al. 2017a), or substituted by five numbered
(Fig. 2). The Doushantuo and Dengying successions units 1–5 with the rank of member (Xiao et al.
areamongpotentialcandidatesfortheEdiacaranSys- 2014a; Zhou et al. 2017b). The recognition of mem-
temchronostratigraphicsubdivision(Narbonneet al. bersintheDoushantuoFormationremainstobefor-
2012;Xiaoet al.2016).ThetypeareaoftheDoushan- malized and here the members are considered
tuoFormationisaroundtheYangtzeGorges,andthe informal (Fig. 2). Lu et al. (2012) studied the Tianji-
type section (‘type locality’) is in the Tianjiayuanzi ayuanzi section and presented as a 170‐m‐thick suc-
section(Zhaoet al.1985;Wanget al.1998;Zhuet al. cession with distinct members, but only the lower
2003; Lu et al. 2012), where it extends between the and upper portions could be measured because the
4 P.Liu&M.Moczydłowska FOSSILSANDSTRATA
Fig.2. GenerallithologicsuccessionandstratigraphicsubdivisionoftheEdiacaranstrataintheYangtzePlatform,SouthChina.TheEdi-
acaranchronostratigraphicsubdivisionandtheagesoftheDoushantuoFormationareaccordingtoCondonetal.(2005)andOggetal.
(2016).LithostratigraphyandsedimentologyoftheDoushantuoFormationiscompiledfromvariouspublicationsreferencedtointhetext
andbyownstudies(Liuetal.2013,2014a,b),buttherecognitionofstratigraphichiatithataremarkedbyverticallinesinredandconven-
tionalsymbolislargelyourinterpretation.Thechronostratigraphiccolumnisdrawnproportionallytothetimeframeanddurationofthe
Ediacaranintervalscorrespondingtoparticularrocksuccessions(lithostratigraphicmembers)butnottotheirthicknesses.Thehiatiatthe
levelsofunconformitiesareofunknownduration.
strata are mainly covered in the middle part of the the valley is the Chenjiayuanzi succession studied
section. As significantly recognized in this section, here(seebelow).
the Doushantuo Formation unconformably overlies
the Nantuo diamictite, and basal and topmost layers
The Doushantuo Formation
of the cap carbonate are strongly disrupted by stro-
lithostratigraphy
matactis‐like cavities, siliceous crusts and sheet
cracks(Luet al.2012;Fig. 2).Thesefeaturesconfirm TheDoushantuoFormationintheYangtzeGorgesis
the inferred unconformities at the base of the underlain by the Cryogenian Nantuo Formation
Doushantuo Formation and at sequence boundary 1 diamictite and overlain by the upper Ediacaran
(SB1) at the top of the cap carbonate (Wang et al. Dengying Formation dolostone. It has well‐defined
1998;Zhuet al.2007b,2013;Luet al.2012). lower and upper boundaries, namely at the base of
The unconformity at the base of the Ediacaran the cap carbonate and the top of organically rich
System involves a hiatus with a duration of ca. 1 Ma black shale at the uppermost part of the formation
(Zhang et al. 2008; Lu et al. 2012; see also under the andatthecontactwiththeoverlyingmassivecrystal-
Jiuqunao section) and is any good example of the lized dolostone of the Dengying Formation (Jiang
newly introduced concept of xenoconformity at this et al. 2006, 2011; Zhu et al. 2007b, 2013; Zhou et al.
stratigraphic level posited by Halverson (2017). Two 2007; Lu et al. 2012; Fig. 2). The Doushantuo For-
additional unconformities in the Tianjiayuanzi sec- mation subdivision into four informal members
tion mark sequence boundary SB2 in the middle of identifiedbylithologiccharacteristicshasbeenrecog-
Member 2,and SB3atthe uppermostMember 3 (Lu nized in numerous studied sections (Wang et al.
et al. 2012). The lower unconformity is covered but 1998;Zhuet al.2003,2013;Zhou&Xiao2007;Zhou
is inferred to occur at 40 m level, whereas the upper et al. 2007, 2017a; McFadden et al. 2008; Jiang et al.
unconformity is well exposed and recognized as the 2011; Lu et al. 2012; Liu et al. 2013, 2014a, b). The
erosional surface with irregular karstic infilling of lower and upper boundaries of individual members
ooidsatthetopofMember3.LocatedneartheTian- are placed at the levels of abrupt lithologic change
jiayuanzi section and parallel to it extending across coincidingwithchangesinthelithofacies(withsome
