Guanling Formation
Guanling Formation
Stratigraphic range : early-mid Anisian (Pelsonian) ~247–245 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Lithology
Location
Coordinates 25°30′N 104°54′E/25.5°N 104.9°E/ 25.5; 104.9
Approximate paleocoordinates 11°42′N 94°12′E/11.7°N 94.2°E/ 11.7; 94.2
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 (including isopods , decapods , mysidaceans and thylacocephalans ) 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 .
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.
Fossil content Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Among others, the following fossils were reported from the formation:
Invertebrates Arthropoda Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Arthropods of the Guanling FormationGenus Species Locality Member Material Notes Image Acanthochirana A. spinifera Luoping Biota Upper Member A preserved exoskeleton An early aegerid prawn Anisaeger A. brevirostrus Luoping Biota Upper Member A preserved exoskeleton An early aegerid prawn Aeger A. luxii Luoping Biota Upper Member A preserved exoskeleton An early aegerid prawn Distaeger D prodigiosus Luoping Biota Upper Member A preserved exoskeleton An early aegerid prawn Judahella J. leii Yunnan Upper Member A specimen An early ostracod Koryncheiros K. luopingensis Luoping Biota Upper Member A preserved exoskeleton A clytiopsid Protamphisopus P. baii Dawazi, Luoping and Ranjiazhai village, Guizhou Upper Member A preserved exoskeleton An amphisopid Sinopemphix S. guizhouensis Dawazi, Luoping Upper Member A preserved exoskeleton A pemphicid Sinosoma S. luopingense Dawazi, Luoping Member II A preserved exoskeleton A chilognatha Tridactylastacus T. sinensis Luoping Biota Upper Member A preserved exoskeleton A litogastroid Yunnanocopia Y. grandis Dawazi and Shangshikan Quarry, Luoping Upper Member A carapace A eucopiid crustacean Y. longicauda A carapace Yunnanolimulus Y. luopingensis Dawazi, Luoping Upper Member A carapace A limulid (horseshoe crab) Yunnanopalinura Y. schrami Luoping Biota Upper Member A preserved exoskeleton An early relative of spiny lobsters
Ammonoidea Ammonites of the Guanling FormationGenus Species Locality Member Material Notes Image Progonoceratites P. pulcher Guizhou A fossilized shell A ceratitid ammonite
Bivalvia Bivalves of the Guanling FormationGenus Species Locality Member Material Notes Image Asoella A. illyrica Eumorphotis E. (Asoella) paradoxica Myophoria M. (Costatoria) goldfussi Pleuromya P. elongata
Brachiopoda Brachiopods of the Guanling FormationGenus Species Locality Member Material Notes Image Lingula L. deitersensis L. marginia L. polaris Pseudospiriferina P. multicostata P. pinguis Punctospirella P. fragilis
Echinoidea Sea Urchins of the Guanling FormationGenus Species Locality Member Material Notes Image Yunnanechinus Y. luopingensis Luoping Biota, Yunnan Member II A specimen An early sea urchin
Vertebrates Fish Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Actinopterygii Ray-finned fish of the Guanling FormationGenus Species Locality Member Material Notes Image Altisolepis A. sinensis Dawazi, Yunnan Upper Member A skeleton A peltopleurid bony fish Diandongichthys D. ocellatus Luoping, Yunnan Upper Member A complete, laterally compressed specimen A basal ginglymodian Diandongperleidus D. denticulatus Dawazi, Yunnan Upper Member A preserved skeleton A perleidiform Feroxichthys F. panzhouensis Xinmin, Panxian Upper Member A skeleton A colobodontid F. yunnanensis Luoping Biota, Yunnan A skeleton Frodoichthys F. luopingensis Dawazi village, Yunnan Upper Member A skeleton An early neopterygian Fuyuanperleidus F. dengi Dawazi village, Yunnan Upper Member A skeleton A fuyuanperleidid Gimlichthys G. dawaziensis Dawazi village, Yunnan Upper Member A skeleton An early neopterygian Gymnoichthys G. inopinatus Dawazi village, Yunnan Upper Member A skeleton An amiiform Habroichthys H. broughi Dawazi village, Yunnan Upper Member A skeleton A peltopleuriform Kyphosichthys K. grandei Luoping, eastern Yunnan Province Upper Member A complete preserved skeleton A kyphosichthyiform Lashanichthys L. sui Yangjuan, Guizhou Upper Member A partial skeleton A lashanichthyid L. yangjuanensis Dawazi Village, Yunnan Upper Member A skeleton Luopingichthys L. bergi Dawazi Village, Yunnan Member II A skeleton A louwoichthyiform Luoxiongichthys L. hyperdorsalis Luoxiong Town, Yunnan Lower member A nearly complete skeleton and skull, a partial skull, and other referred materials A halecomorph Louwoichthys L. pusillus Yunnan Member II A skeleton A louwoichthyid fish Luopingperleidus L. sui Dawazi, Yunnan Upper Member A skeleton A perleidid Marcopoloichthys M. ani Dawazi village, Yunnan Upper Member A complete specimen A teleosteomorph Panxianichthys P. imparilis Xinmin, Guizhou and Yanjuan Upper Member A skeleton A panxianichthyiform Perleidus P. sinensis Dawazi village, Yunnan Upper Member A specimen A perleidid Platysiagum P. sinensis Dawazi, Yunnan Upper Member A skeleton A platysiagid Pteronisculus P. changae Dawazi village, Yunnan Upper Member A skeleton An early ray-finned fish of uncertain affinites P. nielseni Luoping Biota, Yunnan A skeleton Ptycholepis P. huoae Luoping Biota, Yunnan Upper Member A ptycholepiform Robustichthys R. luopingensis Luoping Biota, Yunnan Upper Member A skeleton A Ionoscopiform Saurichthys S. dawaziensis Dawazi village, Yunnan Upper member A broad skull and crushing dentition A saurichthyiform S. spinosa Sinosaurichthys S. longimedialis Yangjuan, Guizhou and Dawazi of Luoping, Yunnan Upper Member A skeleton A saurichthyiform S. longipectoralis A skeleton S. minuta A skeleton Subortichthys S. triassicus Luoping biota, Yunnan Member II A skeleton A subortichthyid Venusichthys V. comptus Luoping biota, Yunnan Member II Multiple skeletons A neopterygian in the monotypic family Venusichthyidae Yelangichthys Y. macrocephalus Xindian, Guizhou Upper Member A broad skull and crushing dentition. A saurichthyiform Yudaiichthys Y. eximius Luoping biota, Yunnan Member II A skeleton A lashanichthyid
Sarcopterygii Lobe-finned fish of the Guanling FormationGenus Species Locality Member Material Notes Image Luopingcoelacanthus L. eurylacrimalis Luoping Biota, Yunnan Upper Member Multiple skeletons A coelacanthiform Luopingcoelacanthus eurylacrimalis Yunnancoelacanthus Y. acrotuberculatus Luoping Biota, Yunnan Upper Member A skeleton A coelacanthiform
Reptiles Ichthyosauria Ichthyosaurs of the Guanling FormationGenus Species Locality Member Materials Notes Image Barracudasauroides B. panxianensis Yangjuan village, Xinmin Upper Member A skeleton A small mixosaurid ichthyosaur ; either a member of its own genus or a species of Mixosaurus Barracudasauroides Phalarodon Mixosaurus Mixosaurus M. kuhnschnyderi Xinzhai Village, Luoping Upper Member A specimen A small mixosaurid ichthyosaur M. luxiensis Huale Village, Luxi Upper Member A largely complete but disarticulated skeleton M. panxianensis Yangjuan Hill locality Middle Member A skeleton M. xindianensis Xindian, Qingshan Pu'an Upper Member Phalarodon P. atavus Upper Member A complete skeleton A small mixosaurid ichthyosaur; might represent a member of its own genus, Contectopalatus P. fraasi Yangjuan Village Upper Member A skull with durophagous dentition. A small mixosaurid ichthyosaur Xinminosaurus X. catactes Near Yangjuan Village, Guizhou Upper Member A nearly complete skeleton A medium-sized early ichthyosaur with durophagous dentition, possibly a member of Cymbospondylidae .
Pseudosuchia Pseudosuchians of the Guanling FormationGenus Species Locality Member Materials Notes Image Chirotherium C. bartheii Zhenfeng County, Guizhou Upper Member Several trackways A pseudosuchian archosaur Qianosuchus Qianosuchus Q. mixtus Xinmin, Panxian Two nearly complete skeletons and a crushed skull An aquatic poposauroid archosaur
Sauropterygia Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Nothosauria Nothosaurs of the Guanling FormationGenus Species Locality Member Materials Notes Image Dawazisaurus D. brevis Dawazisaurus-type locality, Yunnan Member II A nearly complete skeleton exposed in dorsal view A sauropterygian of possible nothosauroid affinities Dawazisaurus Nothosaurus Dikoposichnus D. luopingensis Qingyuan Village, Guizhou, and Luoping Biota, Yunnan Member I 12 trackways and footprints A probable nothosaur ichnotaxon Lariosaurus L. hongguoensis Yangjuan village, Guizhou Upper Member A near-complete skeleton A small Lariosaurinae nothosaur Nothosaurus N. fortihumeralis Luxi Upper Member A partial skeleton consists of the forearm, ribs, hind leg bones, and iliac blade. A nothosaur N. rostellatus Panxian, Guizhou Upper Member A complete skull and incomplete postcranial skeleton N. yangjuanensis Panxian, Guizhou Middle Member A partial skeleton N. zhangi Bed 165 of the Dawazi section, Yunnan Upper Member A complete lower jaw associated with a partial postcranial skeleton Sanchiaosaurus S. dengi Sanchiao in the vicinity of Guiyang and Chinchungchiao, Guizhou Middle member A partial skeleton A nothosaur
Pachypleurosauria Pachypleurosaurs of the Guanling FormationGenus Species Locality Member Materials Notes Image Diandongosaurus D. acutidentatus Dawazi, Yunnan Member II A complete and articulated skeleton with skull A small pachypleurosaur Luopingosaurus Wumengosaurus Dianopachysaurus D. dingi Dawazi, Luoping Member II A near-complete articulated skeleton A keichousaurid pachypleurosaur Dianmeisaurus D. gracilis Luoping, Yunnan Upper Member A small skeleton likely belonging to an immature individual A pachypleurosaur D. mutaensis Northwest of Muta village, Luxi A complete and articulated skeleton exposed in dorsal view Honghesaurus H. longicaudalis Luxi, Yunnan Member II A skeleton A pachypleurosaurid Luopingosaurus L. imparilis Luoping, Yunnan Upper Member A skeleton A pachypleurosaurid Panzhousaurus P. rotundirostris Dapianpo Quarry from Yangjuan Village, Guizhou Upper Member A near-complete skeleton A pachypleurosaur Wumengosaurus W. delicatomandibularis Yangjuan Village, Xinmin Member II A skeleton A small pachypleurosaur W. rotundicarpus Panzhou, Guizhou Member II A specimen
Placodontiformes Placodontiformes of the Guanling FormationGenus Species Locality Member Materials Notes Image Atopodentatus A. unicus Dawazi, Yunnan Upper Member and Member II Several well-preserved specimens A bizarre, likely herbivorous sauropterygian with possible placodontiform affinities Atopodentatus Placodus Placodus P. inexpectatus Yangjuan Village, Xinmin Upper Member A skeleton A medium-sized placodontid placodont , known from a
Saurosphargidae Saurosphargidae of the Guanling FormationGenus Species Locality Member Materials Notes Image Anshunpes A. aquacursor Qingyuan Village, Guizhou Songzikan Member (Member I) A trackway consisting of 10 right and 9 left autopodial (?manus) imprints An ichnotaxon of Saurosphargidae Sinosaurosphargis Largocephalosaurus L. polycarpon Luoping, Yunnan Upper Member A nearly complete and articulated skull and skeleton missing most of its tail A mid-sized basal saurosphargid sauropterygian L. qianensis Panxian, Gauizhou Upper Member Multiple specimens A mid-sized basal saurosphargid sauropterygian Sinosaurosphargis S. yunguinensis Yangmazhai of Luoping County, Yunnan and Yangjian of Pan County, Guizhou Upper Member Multiple specimens A small armoured saurosphargid sauropterygian
Tanysauria Tanysaurians of the Guanling FormationGenus Species Locality Member Materials Notes Image Austronaga A. minuta Waina Village, Yunnan Member II A nearly complete skull articulated, the first six cervical vertebrae, and 65 caudal vertebrae A trachelosaurid Dinocephalosaurus Pectodens Dinocephalosaurus D. orientalis Paxian, Gaizhou and Luoping, Yunnan Member II Multiple specimens A trachelosaurid Gracilicollum G. latens Near Xinmin Village in Panzhou, Guizhou Member II A skull and partial neck A probable trachelosaurid Luxisaurus L. terrestris Near Suomeiluo in Luxi County, Yunnan Upper Member An articulated partial skeleton A tanystropheid Pectodens P. zhenyuensis Luoping, Yunnan Member II A well-preserved and near-complete skeleton A small trachelosaurid