Guanling Formation
| Guanling Formation | |
|---|---|
Ma | |
| Type | Yunnan Provinces |
| Country | China |
| Extent | Yunnan–Guizhou Plateau |
  Guanling Formation (China)  Guanling Formation (Guizhou) | |
The Guanling Formation is a
formation in southwestern China
.
Geology
The formation encompasses two members. The first member is primarily
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
Among others, the following fossils were reported from the formation:
| Genus | Species | Member | Notes | Image |
|---|---|---|---|---|
| Barracudasauroides[6] | B. panxianensis | Upper Member[6][4] | A small | |
| Phalarodon[8][9] | P. cf. fraasi[8] | Upper Member[4] | Known from a skull of a small durophagous dentition. |
|
| P. atavus[9] | Upper Member[4] | A small Contectopalatus . |
||
| Xinminosaurus[10] | X. catactes | Upper Member[4] | A medium-sized early ichthyosaur with durophagous dentition, possibly a member of Cymbospondylidae. |
| Genus | Species | Member | Notes | Image |
|---|---|---|---|---|
| Atopodentatus[11] | A. unicus | Upper Member[11] | A bizarre, likely herbivorous placodontiform affinities,[13] known from several well-preserved specimens. |
|
| Placodus[14] | P. inexpectatus | Upper Member[14][4] | A medium-sized placodontid placodont, known from a complete specimen.[14] |
| Genus | Species | Member | Notes | Image |
|---|---|---|---|---|
| Largocephalosaurus | L. polycarpon[15] | Upper Member [15][4] | A mid-sized basal sauropterygian . |
|
| L. qianensis[16] | Upper Member [16][4] | A mid-sized basal sauropterygian . |
||
| Sinosaurosphargis[17] | S. yunguinensis | Upper Member [17][4] | A small armoured sauropterygian . |
- Altisolepis
- Austronaga[18]
- Dawazisaurus
- Diandongichthys[19]
- Diandongosaurus
- Diandongperleidus
- Dianopachysaurus
- Dianmeisaurus
- Dinocephalosaurus[20]
- Feroxichthys
- Frodoichthys
- Gimlichthys
- Gracilicollum
- Honghesaurus
- Kyphosichthys
- Luopingcoelacanthus
- Luopingosaurus[21]
- Luopingperleidus
- Luoxiongichthys
- Luxisaurus[20]
- Mixosaurus
- Nothosaurus
- Panxianichthys
- Pectodens[20]
- Platysiagum
- Pteronisculus
- Qianosuchus
- Sanchiaosaurus
- Sangiorgioichthys
- Saurichthys
- Sinosaurichthys
- Trachelosaurus
- Venusichthys
- Wumengosaurus
- Yelangichthys
- Yudaiichthys
- Yunnancoelacanthus
References
- ISSN 0022-3360.
- ISSN 0022-3360.
- ISSN 0022-3360.
- ^ ISSN 0012-8252.
- S2CID 263214751.
- ^ S2CID 55171917.
- ^ Maisch, Michael W. (2010). "Phylogeny, systematics, and origin of the Ichthyosauria - the state of the art". Palaeodiversity. 3: 141–214.
- ^ S2CID 54761545.
- ^ .
- .
- ^ S2CID 7770583.
- PMID 27386529.
- PMID 37551884.
- ^ S2CID 9784064.
- ^ .
- ^ .
- ^ .
- .
- .
- ^ S2CID 263634664.
- PMID 36604433.