Guanling Formation
Geological formation in China
From Wikipedia, the free encyclopedia
The Guanling Formation is a Middle Triassic (Anisian or Pelsonian in the regional chronostratigraphy) geologic formation in southwestern China.
UnderliesYangliujing Formation
OverliesJialingjiang Formation
| Guanling Formation | |
|---|---|
| Stratigraphic range: early-mid Anisian (Pelsonian) ~ | |
| Type | Geological formation |
| Underlies | Yangliujing Formation |
| Overlies | Jialingjiang Formation |
| Lithology | |
| Primary | Mudstone, limestone |
| Other | Dolomite |
| Location | |
| Coordinates | 25.5°N 104.9°E |
| Approximate paleocoordinates | 11.7°N 94.2°E |
| Region | Guizhou & Yunnan Provinces |
| Country | China |
| Extent | Yunnan–Guizhou Plateau |
  Guanling Formation (China)  Guanling Formation (Guizhou) | |
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,[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]
Fossil content
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Among others, the following fossils were reported from the formation:
Invertebrates
Arthropoda
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 |  |
| Judahella[7] | J. leii | Yunnan | Upper Member | A specimen | An early ostracod | |
| Koryncheiros | K. luopingensis | Luoping Biota | Upper Member | A preserved exoskeleton | A clytiopsid | |
| Protamphisopus [8] | 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
Bivalvia
Brachiopoda
| Brachiopods of the Guanling Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | 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 Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Member | Material | Notes | Image |
| Yunnanechinus[9] | Y. luopingensis | Luoping Biota, Yunnan | Member II | A specimen | An early sea urchin | |
Vertebrates
Fish
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Actinopterygii
| 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[10] | 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[11] | K. grandei | Luoping, eastern Yunnan Province | Upper Member | A complete preserved skeleton | A kyphosichthyiform |  |
| Lashanichthys[12] | 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[13] | 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[14] | 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[15] | 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[16] | 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 [12] | Y. eximius | Luoping biota, Yunnan | Member II | A skeleton | A lashanichthyid | |
Sarcopterygii
| 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 | |
Reptiles
Ichthyosauria
| Ichthyosaurs of the Guanling Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Member | Materials | Notes | Image |
| Barracudasauroides[17] | B. panxianensis | Yangjuan village, Xinmin | Upper Member[17][4] | A skeleton | A small mixosaurid ichthyosaur; either a member of its own genus[18] or a species of Mixosaurus.[4] |    |
| 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[19][20] | P. atavus[20] | Upper Member[4] | A complete skeleton | A small mixosaurid ichthyosaur; might represent a member of its own genus, Contectopalatus. | ||
| P. fraasi[19] | Yangjuan Village | Upper Member[4] | A skull with durophagous dentition. | A small mixosaurid ichthyosaur | ||
| Xinminosaurus[21] | 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. | |
Pseudosuchia
| Pseudosuchians of the Guanling Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Member | Materials | Notes | Image |
| Chirotherium | C. bartheii | Zhenfeng County, Guizhou | Upper Member | Several trackways | A pseudosuchian archosaur |  |
| Qianosuchus | Q. mixtus | Xinmin, Panxian | Two nearly complete skeletons and a crushed skull | An aquatic poposauroid archosaur | ||
Sauropterygia
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Nothosauria
| 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[22] | D. luopingensis | Qingyuan Village, Guizhou, and Luoping Biota, Yunnan | Member I | 12 trackways and footprints | A probable nothosaur ichnotaxon | |
| Lariosaurus[23] | L. hongguoensis | Yangjuan village, Guizhou | Upper Member | A near-complete skeleton | A small Lariosaurinae nothosaur | |
| Nothosaurus | N. fortihumeralis [24] | Luxi | Upper Member | A partial skeleton consists of the forearm, ribs, hind leg bones, and iliac blade. | A nothosaur | |
| N. rostellatus[25] | Panxian, Guizhou | Upper Member | A complete skull and incomplete postcranial skeleton | |||
| N. yangjuanensis | Panxian, Guizhou | Middle Member | A partial skeleton | |||
| N. zhangi[26] | 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 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[27] | L. imparilis | Luoping, Yunnan | Upper Member | A skeleton | A pachypleurosaurid | |
| Panzhousaurus[28] | 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 Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Member | Materials | Notes | Image |
| Atopodentatus[29] | A. unicus | Dawazi, Yunnan | Upper Member and Member II[29] | Several well-preserved specimens | A bizarre, likely herbivorous[30] sauropterygian with possible placodontiform affinities[31] |   |
| Placodus[32] | P. inexpectatus | Yangjuan Village, Xinmin | Upper Member[32][4] | A skeleton | A medium-sized placodontid placodont, known from a[32] | |
Saurosphargidae
| Saurosphargidae of the Guanling Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Member | Materials | Notes | Image |
| Anshunpes[22] | 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[33] | Luoping, Yunnan | Upper Member [33][4] | A nearly complete and articulated skull and skeleton missing most of its tail | A mid-sized basal saurosphargid sauropterygian | |
| L. qianensis[34] | Panxian, Gauizhou | Upper Member [34][4] | Multiple specimens | A mid-sized basal saurosphargid sauropterygian | ||
| Sinosaurosphargis[35] | S. yunguinensis | Yangmazhai of Luoping County, Yunnan and Yangjian of Pan County, Guizhou | Upper Member [35][4] | Multiple specimens | A small armoured saurosphargid sauropterygian | |
Tanysauria
| Tanysaurians of the Guanling Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Member | Materials | Notes | Image |
| Austronaga[36] | A. minuta | Waina Village, Yunnan | Member II | A nearly complete skull articulated, the first six cervical vertebrae, and 65 caudal vertebrae | A trachelosaurid | .png)  |
| Dinocephalosaurus[37] | D. orientalis | Paxian, Gaizhou and Luoping, Yunnan | Member II | Multiple specimens | A trachelosaurid | |
| Gracilicollum[38] | G. latens | Near Xinmin Village in Panzhou, Guizhou | Member II | A skull and partial neck | A probable trachelosaurid | |
| Luxisaurus[37] | L. terrestris | Near Suomeiluo in Luxi County, Yunnan | Upper Member | An articulated partial skeleton | A tanystropheid | |
| Pectodens[37] | P. zhenyuensis | Luoping, Yunnan | Member II | A well-preserved and near-complete skeleton | A small trachelosaurid | |