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 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.[1]
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.[2]
Fossil content
Among others, the following fossils were reported from the formation:
Ichthyopterygia
| Genus | Species | Member | Notes | Image |
|---|---|---|---|---|
| Barracudasauroides[3] | B. panxianensis | Upper Member[3][1] | A small | |
| Phalarodon[5][6] | P. cf. fraasi[5] | Upper Member[1] | Known from a skull of a small durophagous dentition. |
|
| P. atavus[6] | Upper Member[1] | A small ichthyosaur known from a complete skeleton. Might represent a member of its own genus, Contectopalatus . |
||
| Xinminosaurus[7] | X. catactes | Upper Member[1] | A medium-sized early ichthyosaur with durophagous dentition, possibly a member of Cymbospondylidae . |
Sauropterygia
| Genus | Species | Member | Notes | Image |
|---|---|---|---|---|
| Atopodentatus[8] | A. unicus | Upper Member[8] | A bizarre, likely herbivorous placodontiform affinities,[10] known from several well-preserved specimens. |
|
| Placodus[11] | P. inexpectatus | Upper Member[11][1] | A medium-sized placodontid placodont, known from a complete specimen.[11] |
| Genus | Species | Member | Notes | Image |
|---|---|---|---|---|
| Largocephalosaurus | L. polycarpon[12] | Upper Member [12][1] | A mid-sized basal sauropterygian . |
|
| L. qianensis[13] | Upper Member [13][1] | A mid-sized basal sauropterygian . |
||
| Sinosaurosphargis[14] | S. yunguinensis | Upper Member [14][1] | A small armoured sauropterygian . |
- Austronaga[15]
- Diandongosaurus
- Dianopachysaurus
- Dianmeisaurus
- Dinocephalosaurus[16]
- Gracilicollum
- Honghesaurus
- Kyphosichthys
- Luopingosaurus[17]
- Luoxiongichthys
- Luxisaurus[16]
- Pectodens[16]
- Qianosuchus
- Sanchiaosaurus
- Sinosaurichthys
- Trachelosaurus
- Wumengosaurus
References
- ^ 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.
- PMC 10499374.
- ^ S2CID 9784064.
- ^ a b Cheng, Long; Chen, Xiahong; Zeng, Xiongwei; Cai, Yongjian (2012). "A new eosauropterygian (Diapsida: Sauropterygia) from the Middle Triassic of Luoping, Yunnan Province". Journal of Earth Science. 23: 33–40.
- ^ .
- ^ .
- .
- ^ S2CID 263634664.
- PMID 36604433.