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{{Short description|Geological formation in China}}{{Distinguish|Guanling biota}}

factoids

| period = Anisian| prilithology = Mudstone, limestoneDolomite (rock)>Dolomite| namedfor =| namedby =Guizhou Province>Guizhou & Yunnan Provinces| country = {{CHN}}25.5104.9display=inline,title}}11.794.2display=inline}}| unitof = | subunits =| underlies = Yangliujing Formation| overlies = Jialingjiang Formation| thickness =| extent = Yunnan–Guizhou Plateau| area = China#China Guizhou| relief = 1| width = 250| float = center| places = }}| map_caption =}}The Guanling Formation is a Middle Triassic (Anisian or Pelsonian in the regional chronostratigraphy) geologic formation in southwestern China.

Geology

The formation encompasses two members. The first member is primarily calcareous mudstone and dolomite, indicative of a coastal environment. The second member is a thicker marine sequence of dark micritic limestone with some dolomite. Two distinct fossil assemblages are found in the second member. The older Luoping biota preserves abundant arthropods along with fossils from other invertebrates and vertebrates, which are rare but well-preserved. The slightly younger Panxian fauna has a more diverse and common assortment of marine reptiles such as sauropterygians.JOURNAL, Benton, Michael J., Zhang, Qiyue, Hu, Shixue, Chen, Zhong-Qiang, Wen, Wen, Liu, Jun, Huang, Jinyuan, Zhou, Changyong, Xie, Tao, Tong, Jinnan, Choo, Brian, 2013-10-01, Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction,weblink Earth-Science Reviews, en, 125, 199–243, 10.1016/j.earscirev.2013.05.014, 2013ESRv..125..199B, 0012-8252, A tuff bed in the Luoping biota has been dated to 244.5 ± 2.2 Ma via U-Pb SHRIMP dating. The Luoping biota as a whole was deposited over a period of 340 ± 71 kyr. This estimate is justified by cyclostratigraphic evidence, as indicated by fluctuations of terrestrial proxy metals.JOURNAL, Ma, Zhixin, Wu, Huaichun, Hu, Shixue, Fang, Qiang, Liu, Xiting, Zhou, Changyong, Wen, Wen, Zhang, Qiyue, Huang, Jinyuan, Min, Xiao, 2023-09-26, Temporal duration and preservation mechanism of the Middle Triassic Luoping biota from South China constrained by geochronology and cyclostratigraphy,weblink Global and Planetary Change, 229, 104254, 10.1016/j.gloplacha.2023.104254, 2023GPC...22904254M, 263214751, 0921-8181,

Fossil content

Among others, the following fossils were reported from the formation:Ichthyosauria">

Ichthyopterygia{| class"wikitable" align"center" |+ Ichthyosauria

! Genus !! Species !! Member !! Notes !! ImageBarracudasauroidesJIANG LAST2=SCHMITZ LAST3=HAO LAST4=SUN TITLE=A NEW MIXOSAURID ICHTHYOSAUR FROM THE MIDDLE TRIASSIC OF CHINA DATE=MARCH 30, 2006 ISSUE=1 DOI=10.1671/0272-4634(2006)26[60:ANMIFT]2.0.CO;2 S2CID=55171917 REF=BARRACUDASAUROIDES, B. panxianensis Upper Member A small mixosaurid ichthyosaur, either a member of its own genusMAISCH >FIRST1=MICHAEL W. JOURNAL=PALAEODIVERSITY VOLUME=3 REF=MAISCHICHTHYO, or a species of Mixosaurus. PhalarodonJIANG >FIRST1=DA-YONG FIRST2=SCHMITZ FIRST3=RYOSUKE FIRST4=WIE-CHENG FIRST5=YUAN-LIN JOURNAL=JOURNAL OF PALEONTOLOGY VOLUME=81 PAGES=602–605 JSTOR=4498810 S2CID=54761545 REF=PHALARODONFRAASI, LIU >FIRST1=JUN FIRST2=RYOSUKE FIRST3=DA-YONG FIRST4=SHI-XUE FIRST5=JONATHAN C. FIRST6=OLIVIER FIRST7=MICHAEL J. FIRST8=QI-YUE FIRST9=CHANG-YONG PHALARODON ATAVUS (ICHTHYOSAURIA: MIXOSAURIDAE) FROM SOUTH CHINA, SHOWING POSTCRANIAL ANATOMY AND PERI-TETHYAN DISTRIBUTION >JOURNAL=PALAEONTOLOGY VOLUME=56 PAGES=849–866 BIBCODE=2013PALGY..56..849L REF=PHALARODONATAVUS, P. cf. fraasi >mixosaurid ichthyosaur with durophagous dentition. >| P. atavus>mixosaurid ichthyosaur known from a complete skeleton. Might represent a member of its own genus, Contectopalatus. >| XinminosaurusJIANG LAST2=MOTANI LAST3=HAO LAST4=SCHMITZ LAST5=RIEPPEL LAST6=SUN LAST7=SUN TITLE=NEW PRIMITIVE ICHTHYOSAURIAN (REPTILIA, DIAPSIDA) FROM THE MIDDLE TRIASSIC OF PANXIAN, GUIZHOU, SOUTHWESTERN CHINA AND ITS POSITION IN THE TRIASSIC BIOTIC RECOVERY DATE=2008 ISSUE=10 DOI=10.1016/J.PNSC.2008.01.039 DOI-ACCESS=FREE, X. catactes Upper Member A medium-sized early ichthyosaur with durophagous dentition, possibly a member of Cymbospondylidae. ">

Sauropterygia{| class"wikitable" align"center" width"100%"|+ Placodontiformes

! Genus !! Species !! Member !! Notes !! ImageAtopodentatusCHENG LAST2=CHEN LAST3=SHANG LAST4=WU TITLE=A NEW MARINE REPTILE FROM THE TRIASSIC OF CHINA, WITH A HIGHLY SPECIALIZED FEEDING ADAPTATION DATE=2014 ISSUE=3 DOI=10.1007/S00114-014-1148-4 S2CID=7770583 A. unicus >LAST2=RIEPPEL LAST3=LONG LAST4=FRASER TITLE=THE EARLIEST HERBIVOROUS MARINE REPTILE AND ITS REMARKABLE JAW APPARATUS DATE=2016 ISSUE=5 DOI=10.1126/SCIADV.1501659 PMC=4928886 placodontiform affinities,WOLNIEWICZ LAST2=SHEN LAST3=LI LAST4=SUN LAST5=QIAO LAST6=CHEN LAST7=HU LAST8=LIU TITLE=AN ARMOURED MARINE REPTILE FROM THE EARLY TRIASSIC OF SOUTH CHINA AND ITS PHYLOGENETIC AND EVOLUTIONARY IMPLICATIONS DATE=2023 DOI=10.7554/ELIFE.83163 URL=HTTPS://ELIFESCIENCES.ORG/ARTICLES/83163#CONTENT|PlacodusJIANG LAST2=MOTANI LAST3=HAO LAST4=RIEPPEL LAST5=SUN LAST6=SCHMITZ LAST7=SUN TITLE=FIRST RECORD OF PLACODONTOIDEA (REPTILIA, SAUROPTERYGIA, PLACODONTIA) FROM THE EASTERN TETHYS DATE=2008 ISSUE=3 DOI=10.1671/0272-4634(2008)28[904:FROPRS]2.0.CO;2 S2CID=9784064 P. inexpectatus >placodont, known from a complete specimen. >|{| class="wikitable" align="center" width="100%"|+ Saurosphargidae! Genus !! Species !! Member !! Notes !! ImageLargocephalosaurus L. polycarponCHENG >FIRST1=LONG FIRST2=XIAHONG FIRST3=XIONGWEI FIRST4=YONGJIAN JOURNAL=JOURNAL OF EARTH SCIENCE VOLUME=23 URL=HTTPS://LINK.SPRINGER.COM/ARTICLE/10.1007/S12583-012-0231-Z, Upper Member A mid-sized basal saurosphargid sauropterygian. L. qianensisLI LAST2=JIANG LAST3=CHENG LAST4=WU LAST5=RIEPPEL TITLE=A NEW SPECIES OF LARGOCEPHALOSAURUS (DIAPSIDA: SAUROSPHARGIDAE), WITH IMPLICATIONS FOR THE MORPHOLOGICAL DIVERSITY AND PHYLOGENY OF THE GROUP DATE=2014 ISSUE=1 DOI=10.1017/S001675681300023X saurosphargid sauropterygian. >|SinosaurosphargisLI LAST2=RIEPPEL LAST3=WU LAST4=ZHAO LAST5=WANG TITLE=A NEW TRIASSIC MARINE REPTILE FROM SOUTHWESTERN CHINA DATE=2011 ISSUE=2 DOI=10.1080/02724634.2011.550368 S. yunguinensis >saurosphargid sauropterygian. >|

• AustronagaJOURNAL, Wang, W., Lei, H., Li, C., 2023, A small-sized dinocephalosaurid archosauromorph from the Middle Triassic of Yunnan, southwestern China, Vertebrata PalAsiatica, 62, 1, 13, 10.19615/j.cnki.2096-9899.231013,weblink
• Diandongosaurus
• Dianopachysaurus
• Dianmeisaurus
• DinocephalosaurusJOURNAL, Lu, Yu-Ting, Liu, Jun, 2023-10-02, A new tanystropheid (Diapsida: Archosauromorpha) from the Middle Triassic of SW China and the biogeographical origin of Tanystropheidae, Journal of Systematic Palaeontology, en, 21, 1, 10.1080/14772019.2023.2250778, 2023JSPal..2150778L, 263634664, 1477-2019,
• Gracilicollum
• Honghesaurus
• Kyphosichthys
• LuopingosaurusJOURNAL, Xu, G.-H., Shang, Q.-H., Wang, W., Ren, Y., Lei, H., Liao, J.-L., Zhao, L.-J., Li, C., 2023, A new long-snouted marine reptile from the Middle Triassic of China illuminates pachypleurosauroid evolution, Scientific Reports, 13, 1, 16, 10.1038/s41598-022-24930-y, free, 36604433, 2045-2322, 9816097, 2023NatSR..13...16X,
• Luoxiongichthys
• Luxisaurus
• Pectodens
• Qianosuchus
• Sanchiaosaurus
• Sinosaurichthys
• Trachelosaurus
• Wumengosaurus

References

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