Guanling Formation | |
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Stratigraphic range: early-mid Anisian (Pelsonian) ~ | |
Type | Geological formation |
Underlies | Yangliujing Formation |
Overlies | Jialingjiang Formation |
Lithology | |
Primary | Mudstone, limestone |
Other | Dolomite |
Location | |
Coordinates | 25°30′N104°54′E / 25.5°N 104.9°E |
Approximate paleocoordinates | 11°42′N94°12′E / 11.7°N 94.2°E |
Region | Guizhou & Yunnan Provinces |
Country | China |
Extent | Yunnan–Guizhou Plateau |
The Guanling Formation is a Middle Triassic (Anisian or Pelsonian in the regional chronostratigraphy) geologic formation in southwestern China.
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, [1] decapods, [2] mysidaceans and thylacocephalans [3] ) 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. [4]
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. [5]
Color key
| Notes Uncertain or tentative taxa are in small text; |
Among others, the following fossils were reported from the formation:
Color key
| Notes Uncertain or tentative taxa are in small text; |
Arthropods of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Material | Notes | Image |
Acanthochirana [6] | A. spinifera | Luoping Biota | Upper Member | A preserved exoskeleton | An early aegerid prawn | |
Anisaeger [6] | 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 [6] | D prodigiosus | Luoping Biota | Upper Member | A preserved exoskeleton | An early aegerid prawn | |
Koryncheiros | K. luopingensis | Luoping Biota | Upper Member | A preserved exoskeleton | A clytiopsid | |
Protamphisopus [7] | 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 piny lobsters | |
Ammonites of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Material | Notes | Image |
Progonoceratites | P. pulcher | Guizhou | A fossilized shell | A ceratitid ammonite | ||
Bivalves of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Material | Notes | Image |
Asoella | A. illyrica | |||||
Eumorphotis | E. (Asoella) paradoxica | |||||
Myophoria | M. (Costatoria) goldfussi | |||||
Pleuromya | P. elongata | |||||
Sea Urchins of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Material | Notes | Image |
Yunnanechinus [8] | Y. luopingensis | Luoping Biota, Yunnan | Member II | A specimen | An early sea urchin | |
Color key
| Notes Uncertain or tentative taxa are in small text; |
Ray-finned fish of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Material | Notes | Image |
Altisolepis | A. sinensis | Dawazi, Yunnan | Upper Member | A skeleton | A peltopleurid bony fish | ![]() ![]() |
Diandongichthys [9] | 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 [10] | K. grandei | Luoping, eastern Yunnan Province | Upper Member | A complete preserved skeleton | A kyphosichthyiform | |
Lashanichthys [11] | 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 [12] | 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 [13] | 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 [14] | Luoping Biota, Yunnan | A skeleton | ||||
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 [15] | 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 [11] | Y. eximius | Luoping biota, Yunnan | Member II | A skeleton | A lashanichthyid | |
Lobe-finned fish of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Material | Notes | Image |
Luopingcoelacanthus | L. eurylacrimalis | Luoping Biota, Yunnan | Upper Member | Multiple skeletons | A coelacanthiform | ![]() |
Yunnancoelacanthus | Y. acrotuberculatus | Luoping Biota, Yunnan | Upper Member | A skeleton | A coelacanthiform | |
Ichthyosaurs of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Materials | Notes | Image |
Barracudasauroides [16] | B. panxianensis | Yangjuan village, Xinmin | Upper Member [16] [4] | A skeleton | A small mixosaurid ichthyosaur; either a member of its own genus [17] or a species of Mixosaurus . [4] | ![]() ![]() ![]() |
Mixosaurus | M. kuhnschnyderi | Xinzhai Village, Luoping | Upper Member | 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 [18] [19] | P. atavus [19] | Upper Member [4] | A complete skeleton | A small mixosaurid ichthyosaur; might represent a member of its own genus, Contectopalatus . | ||
P. fraasi [18] | Yangjuan Village | Upper Member [4] | A skull with durophagous dentition. | A small mixosaurid ichthyosaur | ||
Xinminosaurus [20] | X. catactes | Near Yangjuan Village, Guizhou | Upper Member [4] | A nearly complete skeleton | A medium-sized early ichthyosaur with durophagous dentition, possibly a member of Cymbospondylidae. | |
Pseudosuchians of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Materials | Notes | Image |
Qianosuchus | Q. mixtus | Xinmin, Panxian | Two nearly complete skeletons and a crushed skull | An aquatic poposauroid archosaur | ![]() | |
Color key
| Notes Uncertain or tentative taxa are in small text; |
Nothosaurs of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | 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 | ![]() ![]() |
Dikoposichnus [21] | D. luopingensis | Qingyuan Village, Guizhou, and Luoping Biota, Yunnan | Member I | 12 trackways and footprints | A probable nothosaur ichnotaxon | |
Nothosaurus | N. yangjuanensis | Panxian, Guizhou | Middle Member | A partial skeleton | A nothosaur | |
Sanchiaosaurus | S. dengi | Sanchiao in the vicinity of Guiyang and Chinchungchiao, Guizhou | Middle member | A partial skeleton | A nothosaur | |
Pachypleurosaurs of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Materials | Notes | Image |
Diandongosaurus | D. acutidentatus | Dawazi, Yunnan | Member II | A complete and articulated skeleton with skull | A small pachypleurosaur | ![]() ![]() |
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 [22] | L. imparilis | Luoping, Yunnan | Upper Member | A skeleton | A pachypleurosaurid | |
Wumengosaurus | W. delicatomandibularis | Yangjuan Village, Xinmin | Member II | A skeleton | A small pachypleurosaur | |
W. rotundicarpus | Panzhou, Guizhou | Member II | A specimen | |||
Placodontiformes of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Materials | Notes | Image |
Atopodentatus [23] | A. unicus | Dawazi, Yunnan | Upper Member and Member II [23] | Several well-preserved specimens | A bizarre, likely herbivorous [24] sauropterygian with possible placodontiform affinities [25] | ![]() ![]() |
Placodus [26] | P. inexpectatus | Yangjuan Village, Xinmin | Upper Member [26] [4] | A skeleton | A medium-sized placodontid placodont, known from a [26] |
Saurosphargidae of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Materials | Notes | Image |
Anshunpes [21] | 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 | ![]() |
Largocephalosaurus | L. polycarpon [27] | Luoping, Yunnan | Upper Member [27] [4] | A nearly complete and articulated skull and skeleton missing most of its tail | A mid-sized basal saurosphargid sauropterygian | |
L. qianensis [28] | Panxian, Gauizhou | Upper Member [28] [4] | Multiple specimens | A mid-sized basal saurosphargid sauropterygian | ||
Sinosaurosphargis [29] | S. yunguinensis | Yangmazhai of Luoping County, Yunnan and Yangjian of Pan County, Guizhou | Upper Member [29] [4] | Multiple specimens | A small armoured saurosphargid sauropterygian | |
Tanysaurians of the Guanling Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Locality | Member | Materials | Notes | Image |
Austronaga [30] | A. minuta | Waina Village, Yunnan | Member II | A nearly complete skull articulated, the first six cervical vertebrae, aand 65 caudal vertebrae | A trachelosaurid | ![]() ![]() |
Dinocephalosaurus [31] | D. orientalis | Paxian, Gaizhou and Luoping, Yunnan | Member II | Multiple specimens | A trachelosaurid | |
Gracilicollum [32] | G. latens | Near Xinmin Village in Panzhou, Guizhou | Member II | A skull and partial neck | A probable trachelosaurid | |
Luxisaurus [31] | L. terrestris | Near Suomeiluo in Luxi County, Yunnan | Upper Member | An articulated partial skeleton | A tanystropheid | |
Pectodens [31] | P. zhenyuensis | Luoping, Yunnan | Member II | A well-preserved and near-complete skeleton | A small trachelosaurid | |