The Ermaying Formation is a geological formation of Anisian (Middle Triassic) age in north-central China.[1] It is found across much of the Ordos Basin, at outcrops within the provinces of Shaanxi, Shanxi, and Inner Mongolia. It is composed of up to 600 m thick sequence of mudstone and sandstone, overlying the Heshanggou Formation and underlying the Tongchuan Formation.[2][3] In the southern part of the Ordos Basin, the Zhifang Formation is equivalent to the Ermaying Formation.[4]
| Ermaying Formation | |
|---|---|
| Stratigraphic range: Anisian ~ | |
| Type | Geological formation |
| Sub-units | Two Members |
| Underlies | Tongchuan Formation |
| Overlies | Heshanggou Formation |
| Thickness | Up to 600 metres (2,000 ft) |
| Lithology | |
| Primary | Mudstone, sandstone |
| Other | Tuff |
| Location | |
| Coordinates | 37°26′15″N 110°39′06″E / 37.43750°N 110.65167°E |
| Approximate paleocoordinates | 38°12′N 90°30′E / 38.2°N 90.5°E |
| Region | Shaanxi, Shanxi, Inner Mongolia |
| Country |  China |
  Ermaying Formation (China)  Ermaying Formation (Shanxi) | |
The Ermaying Formation is divided into two members, each with a distinctive assemblage of tetrapod fossils. A 2013 study used SHRIMP U-Pb radiometric dating to assign an imprecise age of 245.9 ± 3.2 Ma for the upper member.[5] A 2018 study assigned a more precise age of around 243.53 Ma based on three ash samples near the base of the upper member. This would indicate that the Upper Ermaying Formation is no older than the late Anisian stage.[6]
A few studies apply the name "Ermaying Formation" to a sedimentary unit in the Yanshan belt, a fold-thrust belt northeast of Beijing. In the Yanshan belt, reported exposures of the formation are dated to the Late Triassic, lying below the Early Jurassic Xingshikou Formation.[7][8] The Yanshan belt exposures are also known as the Huzhangzi Formation, an alternative name proposed to reflect their chronological and geographic divergence from exposures in the Ordos Basin.[8][6][4]
Paleobiota
editThe Ermaying Formation is notable for its diversity of well-preserved tetrapods.[3]
The upper member occupies most of a biozone historically known as the Sinokannemeyeria fauna.[9][6] This fossil assemblage has more recently been termed the Sinokannemeyeria-Shansisuchus Assemblage Zone, including approximately coeval sediments of the Kelamayi Formation in Xinjiang. The biozone also extends up to the early part of the Tongchuan Formation.[10]
Tetrapod burrows are known from the formation, occupying both large and small size classes. The larger burrow is reniform (kidney-shaped) in cross section, about 13 centimetres (5.1 in) in height and 30 centimetres (12 in) in width. It shallowly slopes down when seen from the side and smoothly undulates when seen from above. Scatches and grooves are readily visible on the inside. The burrow-maker was medium-sized animal, likely a juvenile dicynodont. The smaller burrows are low tapered chambers with incomplete or collapsed entry ramps. They may have been dug out by procolophonids or juvenile cynodonts.[11]
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Synapsids
editApart from the taxa listed here, fossils of an unnamed genus of kannemeyeriiform dicynodont have been found in the Upper Ermaying Formation at the Sanjiao site in Shanxi Province. Not counting Shansiodon, this unnamed form is the third "kannemeyeriid" genus known from the Upper Member, as it is distinct from both Parakannemeyeria and Sinokannemeyeria.[12]
Cynodonts
edit| Cynodonts of the Ermaying Formation | |||||
|---|---|---|---|---|---|
| Taxa | Species | Material | Member | Notes | Images |
| Sinognathus[13] | S. gracilis[13] | A skull[13] | Upper[9][14][15] | A sinognathine trirachodontid cynodont. | |
Dicynodonts
edit| Dicynodonts of the Ermaying Formation | |||||
|---|---|---|---|---|---|
| Taxa | Species | Material | Member | Notes | Images |
| Parakannemeyeria[16] | P. dolicocephala[16] | A skull and partial skeleton.[16][14] | Upper[14] | A "kannemeyeriid" dicynodont, the type species of Parakannemeyeria.[16] | |
| P. ningwuensis[17] | Skulls and partial skeletons.[14] | Upper[14] | A "kannemeyeriid" dicynodont. | ||
| P. shenmuensis[18] | A skull[14] | Upper[14] | A "kannemeyeriid" dicynodont. | ||
| P. xingxianensis[18] | A skull and postcrania.[14] | Lower[14] | A "kannemeyeriid" dicynodont. Sometimes considered a junior synonym of P. ningwuensis.[19] | ||
| P. youngi[17] | Multiple partial skeletons.[14][20] | Lower?,[9][20] Upper[9][14] | A "kannemeyeriid" dicynodont.[20] | ||
| Shaanbeikannemeyeria[18] | S. buerdongia[21] | A skull and postcrania.[21][14] | Lower[14] | A "kannemeyeriid" dicynodont. Sometimes considered a species of Kannemeyeria or Rechnisaurus,[19] and more recently as a junior synonym of S. xilougouensis.[20] | |
| S. xilougouensis[18] | Multiple partial skeletons.[20] | Lower[9][14][20] | A "kannemeyeriid" dicynodont, the type species of Shaanbeikannemeyeria.[20] Sometimes considered a species of Kannemeyeria or Rechnisaurus,[19] though its validity was strongly supported by a 2022 redescription.[20] | ||
| Shansiodon[22] | S. shaabeiensis[18] | A skull[14] | Upper[14] | A shansiodontid dicynodont. | |
| S. wangi[22] | A nearly complete skeleton with skull.[22][14] | Upper[9][14] | A shansiodontid dicynodont, the type species of Shansiodon.[22] | ||
| S. wuhsiangensis[22] | Skulls and postcrania.[22][14] | Upper[14] | A shansiodontid dicynodont. | ||
| S. wupuensis[18] | A skull[14] | Upper[14] | A shansiodontid dicynodont. | ||
| Sinokannemeyeria[23] | S. pearsoni[23] | Multiple partial skeletons.[23][14] | Upper[14] | A "kannemeyeriid" dicynodont, the type species of Sinokannemeyeria.[23] |  |
| S. sanchuanheensis[18] | A skull[14] | Upper[9][14] | A "kannemeyeriid" dicynodont, sometimes considered a species of Kannemeyeria.[9] | ||
| S. yingchiaoensis[17] | Skulls and partial skeletons.[14] | Upper[14] | A "kannemeyeriid" dicynodont. | ||
Therocephalians
edit| Therocephalians of the Ermaying Formation | |||||
|---|---|---|---|---|---|
| Taxa | Species | Material | Member | Notes | Images |
| Nothogomphodon | N. sanjiaoensis[24] | A partial jaw.[24] | Upper[24] | A baurioid therocephalian.[24] | |
| Ordosia[25] | O. youngi[25] | A partial skull and postcrania.[25][26] | Lower[14][15][26] | A baurioid therocephalian, sometimes considered a species of Ordosiodon.[14][26] | |
| Ordosiodon[27] | O. lincheyuensis[27] | A partial jaw.[27][14][26] | Lower[9][14][15][26] | A baurioid therocephalian,[14][26][28] initially misidentified as a diademodontid cynodont.[27][9][15] | |
| Traversodontoides[29] | T. wangwuensis[29] | A skull and postcrania.[29][14] | Upper[9][14][15] | A traversodontid cynodont or baurioid therocephalian.[15] | |
| Yikezhaogia[30] | Y. megafenestrala[30] | A skull and postcrania.[30][26] | Lower[26] | A therocephalian of uncertain affinities,[26] potentially a "scaloposaur".[30] | |
Reptiles
edit| Reptiles of the Ermaying Formation | |||||
|---|---|---|---|---|---|
| Genus / Taxon | Species | Material | Member | Notes | Images |
| "Chasmatosuchus" | "C. ultimus"[31] | A partial skull preserving the snout, jaw, and palate.[32] | Upper[32] | A dubious (crown)-archosaur[32][33] previously misidentified as the proterosuchid Chasmatosuchus.[31] | |
| Eumetabolodon[34] | E. bathycephalus[34] | An incomplete skull.[34] | Lower[20] | A procolophonid which is much more common in the Heshanggou Formation.[34] | |
| Fenhosuchus[31] | F. cristatus[31] | Fragmentary skeletons. | Upper[9][15] | A dubious archosauriform, possibly a chimera of fossils from Shansisuchus and paracrocodylomorph archosaurs.[10] | |
| Guchengosuchus[35] | G. shiguaiensis[35] | A partial skeleton consisting of an incomplete skull, vertebrae, ribs, and (now missing) forelimb material.[35][36] | Lower[36] | A basal erythrosuchid archosauriform.[36] | |
| Halazhaisuchus[37] | H. qiaoensis[37] | A partial skeleton consisting of forelimb and shoulder material, vertebrae, ribs, and osteoderms.[37][38] | Lower[38] | A euparkeriid archosauriform.[38] | |
| Neoprocolophon[39] | N. asiaticus[39] | A skull.[39] | Upper[9][15] | A procolophonid. | |
| Paoteodon[40] | P. huanghoensis[40] | A maxilla fragment.[40] | Lower[9][15] | A dubious procolophonid. | |
| Shansisuchus[31] | S. heiyuekouensis[31] | Fragmentary skeletons.[41] | Upper[10] | An erythrosuchid archosauriform of uncertain validity.[10] |  |
| S. kuyeheensis[18] | A partial skeleton consisting of an incomplete skull, vertebrae, humerus, and shoulder material[33] | Upper[33] | An erythrosuchid archosauriform of uncertain validity.[33][10] | ||
| S. shansisuchus[31] | Multiple partial skeletons.[41][33] | Upper[33] | A large erythrosuchid archosauriform, the type species of Shansisuchus.[41][33] | ||
| "Turfanosuchus" | "T. shageduensis"[37] | A partial skeleton consisting of limb and shoulder material, vertebrae, and a mandible.[37][38] | Lower[38] | A dubious archosauriform, presumably a euparkeriid unrelated to Turfanosuchus dabanensis.[38] | |
| "Wangisuchus"[31] | "W. tzeyii"[31] | Maxillae.[38] | Upper[9][15][38] | A dubious archosauriform.[38] | |
References
edit- ^ Desojo, J. B. (2013). Anatomy, Phylogeny and Palaeobiology of Early Archosaurs and their Kin. ISBN 978-1862393615.
- ^ Zhu, Zhicai; Liu, Yongqing; Kuang, Hongwei; Newell, Andrew J.; Peng, Nan; Cui, Mingming; Benton, Michael J. (2022-09-01). "Improving paleoenvironment in North China aided Triassic biotic recovery on land following the end-Permian mass extinction". Global and Planetary Change. 216: 103914. Bibcode:2022GPC...21603914Z. doi:10.1016/j.gloplacha.2022.103914. ISSN 0921-8181.
- ^ a b Sues, Hans-Dieter; Fraser, Nicholas C. (2010). Triassic life on land : the great transition. New York: Columbia University Press. ISBN 978-0231135221.
- ^ a b Meng, Qing-Ren; Wu, Guo-Li; Fan, Long-Gang; Wei, Hong-Hong (2019-03-01). "Tectonic evolution of early Mesozoic sedimentary basins in the North China block". Earth-Science Reviews. 190: 416–438. Bibcode:2019ESRv..190..416M. doi:10.1016/j.earscirev.2018.12.003. ISSN 0012-8252. S2CID 135264897.
- ^ Liu, Jun; Li, Lu; Li, Xing-Wen (2013). "SHRIMP U-Pb zircon dating of the Triassic Ermaying and Tongchuang formations in Shanxi, China and its stratigraphic implications" (PDF). Vertebrata PalAsiatica. 51 (2): 162–168.
- ^ a b c Liu, Jun; Ramezani, Jahandar; Li, Lu; Shang, Qing-Hua; Xu, Guang-Hui; Wang, Yan-Yin; Yang, Jia-Sheng (2018). "High-precision temporal calibration of Middle Triassic vertebrate biostratigraphy: U-Pb zircon constraints for the Sinokannemeyeria Fauna and Yonghesuchus". Vertebrata PalAsiatica. 56 (1): 16–24. doi:10.19615/j.cnki.1000-3118.170808.
- ^ Meng, Qing-Ren; Wei, Hong-Hong; Wu, Guo-Li; Duan, Liang (2014-01-25). "Early Mesozoic tectonic settings of the northern North China craton". Tectonophysics. 611: 155–166. Bibcode:2014Tectp.611..155M. doi:10.1016/j.tecto.2013.11.015. ISSN 0040-1951.
- ^ a b Wei, HongHong; Wu, GuoLi; Duan, Liang (2015-04-01). "Revisiting Triassic stratigraphy of the Yanshan belt". Science China Earth Sciences. 58 (4): 491–501. Bibcode:2015ScChD..58..491W. doi:10.1007/s11430-014-5042-x. ISSN 1869-1897. S2CID 130672024.
- ^ a b c d e f g h i j k l m n o Sun, Ai-Lin (1980). "Late Permian and Triassic terrestrial tetrapods of north China" (PDF). Vertebrata PalAsiatica (in Chinese). 18 (2): 100–110.
- ^ a b c d e Liu, Jun; Sullivan, Corwin (2017). "New discoveries from the Sinokannemeyeria-Shansisuchus Assemblage Zone: 3. Archosauriformes from Linxian, Shanxi, China". Vertebrata PalAsiatica. 55 (2): 110–128.
- ^ Yang, Jia-Sheng; Yi, Jian; Dong, Li-Yang; Liu, Jun (2018). "Tetrapod burrows from the Triassic Ermaying Formation of Shaanxi, China". Vertebrata PalAsiatica. 56 (2): 147–156. doi:10.19615/j.cnki.1000-3118.180319.
- ^ Liu, Jun (2015). "New discoveries from the Sinokannemeyeria-Shansisuchus Assemblage Zone: 1. Kannemeyeriiformes from Shanxi, China". Vertebrata PalAsiatica. 53 (1): 16–28.
- ^ a b c Young, Chung-Chien (1959). "Note on the first cynodont from the Sinokannemeyeria-faunas in Shansi, China" (PDF). Vertebrata PalAsiatica. 3 (3): 124–132.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai Sigogneau-Russell, Denise; Sun, Ai-Lin (1981). "A brief review of Chinese synapsids". Geobios. 14 (2): 275–279. Bibcode:1981Geobi..14..275S. doi:10.1016/S0016-6995(81)80012-5.
- ^ a b c d e f g h i j Zhen, Shuonan; Zhen, Baiming; Mateer, Niall J.; Lucas, Spencer G. (1985). "The Mesozoic reptiles of China" (PDF). Bulletin of the Geological Institutions of the University of Uppsala. 11: 133–150.
- ^ a b c d Sun, Ai-Lin (1960). "On a new genus of Kannemeyerids from Ningwu, Shansi" (PDF). Vertebrata PalAsiatica. 4 (2): 67–81.
- ^ a b c Sun, Ai-Lin (1963). "The Chinese kannemeyerids". Palaeontologia Sinica, Series C (in Chinese). 17: 71–109.
- ^ a b c d e f g h Cheng, Z.W. (1980). "古脊椎动物化石" [Vertebrate fossils]. 陕甘宁盆地中生代地层古生物 [Mesozoic stratigraphy and paleontology of basins of Shanxi, Gangsu, and Ningxia] (in Chinese). Beijing: Chinese Academy of Geological Sciences. pp. 115–188.
- ^ a b c Fröbisch, Jörg (2009). "Composition and similarity of global anomodont-bearing tetrapod faunas". Earth-Science Reviews. 95 (3–4): 119–157. Bibcode:2009ESRv...95..119F. doi:10.1016/j.earscirev.2009.04.001.
- ^ a b c d e f g h i Liu, Jun (2022). "On kannemeyeriiform dicynodonts from the Shaanbeikannemeyeria Assemblage Zone of the Ordos Basin, China". Vertebrata PalAsiatica. 60 (3): 212–248. doi:10.19615/j.cnki.2096-9899.220601.
- ^ a b Li, Jin-lin (1980). "Kannemeyeria Fossil from Inner Mongolia" (PDF). Vertebrata PalAsiatica (in Chinese). 18 (2): 94–99.
- ^ a b c d e f Yeh, Hsiang-K'uei (1959). "New Dicynodont from Sinokannemeyeria-Fauna from Shansi" (PDF). Vertebrata PalAsiatica. 3 (4): 187–204.
- ^ a b c d Young, C. C. (1937). "On the Triassic Dicynodonts from Shansi *". Bulletin of the Geological Society of China. 17 (3–4): 393–412. doi:10.1111/j.1755-6724.1937.mp173-4011.x. ISSN 1673-274X.
- ^ a b c d Liu, Jun; Abdala, Fernando (2015). "New discoveries from the Sinokannemeyeria-Shansisuchus Assemblage Zone: 2. A new species of Nothogomphodon (Therapsida: Therocephalia) from the Ermaying Formation of Shanxi, China" (PDF). Vertebrata PalAsiatica. 53 (2): 123–132.
- ^ a b c Hou, Lianhai (1979). "On a New Theriodont from Inner Mongolia" (PDF). Vertebrata PalAsiatica (in Chinese). 17 (2): 121–130.
- ^ a b c d e f g h i Sun, Ai-Lin (1991). "A Review of Chinese Therocephalian Reptiles" (PDF). Vertebrata PalAsiatica (in Chinese). 21 (2): 85–94.
- ^ a b c d Young, Chung-chien (1961). "On A New Cynodont from NW Shansi" (PDF). Vertebrata PalAsiatica (in Chinese and English). 5 (2): 109–113.
- ^ Sidor, Christian A.; Kulik, Zoe T.; Huttenlocker, Adam K. (2021-10-01). "A new bauriamorph therocephalian adds a novel component to the Lower Triassic tetrapod assemblage of the Fremouw Formation (Transantarctic Basin) of Antarctica". Journal of Vertebrate Paleontology. 41 (6). Bibcode:2021JVPal..41E1510S. doi:10.1080/02724634.2021.2081510. ISSN 0272-4634. S2CID 250663346.
- ^ a b c Young, Chung-chien. "A New Genus of Traversodontidae in Jiyuan, Honan" (PDF). Vertebrata PalAsiatica (in Chinese). 12 (3): 203–211.
- ^ a b c d Li, Yuhe (1984). "On a New Scaloposaurid from Inner Mongolia" (PDF). Vertebrata PalAsiatica (in Chinese). 22 (1): 21–28.
- ^ a b c d e f g h i Young, C.C. (1964). "The pseudosuchians in China". Palaeontologia Sinica, New Series C. 19: 1–205.
- ^ a b c Liu, Jun; Butler, Richard; Sullivan, Corwin; Ezcurra, Martin (2015-09-03). "'Chasmatosaurus ultimus,' a putative proterosuchid archosauriform from the Middle Triassic, is an indeterminate crown archosaur". Journal of Vertebrate Paleontology. 35 (5): e965779. Bibcode:2015JVPal..35E5779L. doi:10.1080/02724634.2015.965779. ISSN 0272-4634. S2CID 86567970.
- ^ a b c d e f g Ezcurra, Martín D. (2016-04-28). "The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriforms". PeerJ. 4: e1778. doi:10.7717/peerj.1778. ISSN 2167-8359. PMC 4860341. PMID 27162705.
- ^ a b c d Li, Jin Ling (1983). "Tooth replacement in a new genus of procolophonid from the early Triassic of China" (PDF). Palaeontology. 26 (3): 567–583.
- ^ a b c Peng, J. (1991). "A new genus of Proterosuchia from Lower Triassic of Shaanxi, China" (PDF). Vertebrata PalAsiatica (in Chinese). 29: 95–107.
- ^ a b c Butler, Richard J.; Ezcurra, Martín D.; Liu, Jun; Sookias, Roland B.; Sullivan, Corwin (2019-02-19). "The anatomy and phylogenetic position of the erythrosuchid archosauriform Guchengosuchus shiguaiensis from the earliest Middle Triassic of China". PeerJ. 7: e6435. doi:10.7717/peerj.6435. ISSN 2167-8359. PMC 6385703. PMID 30809443.
- ^ a b c d e Wu, Xiaochun (1982). "Two Pseudosuchian Reptiles from Shan-Gan-Ning Basin" (PDF). Vertebrata PalAsiatica. 20 (4): 291–301.
- ^ a b c d e f g h i Sookias, Roland B.; Sullivan, Corwin; Liu, Jun; Butler, Richard J. (2014-11-25). "Systematics of putative euparkeriids (Diapsida: Archosauriformes) from the Triassic of China". PeerJ. 2: e658. doi:10.7717/peerj.658. ISSN 2167-8359. PMC 4250070. PMID 25469319.
- ^ a b c Young, Chung-Chien (1957). "Neoprocolophon asiaticus, a new cotylosaurian reptile from China" (PDF). Vertebrata PalAsiatica. 1: 1–7.
- ^ a b c Chow, Minchen; Sun, Ai-Lin (1960). "A new procolophonid from north-western Shansi" (PDF). Vertebrata PalAsiatica. 4 (1): 11–13.
- ^ a b c Runfu, Wang; Shichao, Xu; Xiaochun, Wu; Chun, Li; Suozhu, Wang (2013). "A New Specimen of Shansisuchus shansisuchus Young, 1964 (Diapsida: Archosauriformes) from the Triassic of Shanxi, China". Acta Geologica Sinica - English Edition. 87 (5): 1185–1197. Bibcode:2013AcGlS..87.1185W. doi:10.1111/1755-6724.12145. ISSN 1000-9515.