Xitun Formation
Stratigraphic range:
TypeGeological formation
Unit ofCuifengshan Group[1]
UnderliesGuijiatun Formation[2]
OverliesXiaxishancun Formation[2]
Lithology
PrimaryCalciferous mudstones[2]
Location
Coordinates25°29.853'N and 103°46.309'E[2]
RegionYunnan Province
Country China
ExtentQujing
Type section
Named forXitun village

The Xitun Formation is a palaeontological formation which is named after Xitun village in Qujing, a location in South China. This formation includes many remains of fossilized fish and plants of the Early Devonian period (Late Lochkovian).[1][2] It was originally referred to as the Xitun Member of the Cuifengshan Formation (now the Cuifengshan Group).[3]

Fossil content

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
 Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Vertebrates

Acanthodians

Acanthodians reported from the Xitun Formation
GenusSpeciesPresence MaterialNotesImages
Ischnacanthidae Genus indet. Qujing.[3] 4 isolated scales (V7218.1, 3, 6 & 8) & 2 longitudinal sections (V7218.4 & 7).[3] Similar to Ischnacanthus & Acanthodes, may be referrable to Youngacanthus.
Nostolepis N. amplifica Xitun, Xishan subdistrict, Qujing.[4] 43 trunk scales.[4]
N. consueta Xitun, Xishan subdistrict, Qujing.[4] Around 25 trunk scales.[4]
N. digitus Xitun , Xishan subdistrict, Qujing.[4] 28 trunk scales.[4]
N. qujingensis Xitun, Xishan subdistrict, Qujing.[4] 19 trunk scales.[4]
N. striata Xitun, Xishan subdistrict, Qujing.[4] 69 trunk scales.[4]
N. sp. indet. Qujing.[3] Body scales.[3]
Youngacanthus Y. gracilis Qujing.[3] Jaw elements & teeth.[3] An ischnacanthid.

Actinopterygians

Actinopterygians reported from the Xitun Formation
GenusSpeciesPresence MaterialNotesImages
Meemannia M. eos Xitun village, Qujing.[5] An early ray-finned fish, formerly thought to be a lobe finned fish.[6]

Chondrichthyes

Chondrichthyes reported from the Xitun Formation
GenusSpeciesPresence MaterialNotesImages
Changolepis C. tricuspidus Qujing.[3] 10 scales of various growth stages.[3]
Chondrichthyes Genus indet. Qujing.[3] 4 isolated teeth (V7221.1, 2, 3 & 4). May belong to Gualepis or Changolepis.
Gualepis G. elegans Xitun, Qilin district, Qujing.[7] Thousands of isolated scales.[3][7]
Ohiolepis? O.? xitunensis Qujing.[3] A complete scale (V7233.1) & an incomplete scale (V7223.2).[3]
Peilepis P. solida Qujing.[3] A body scale (V7222).[3]

Jawless fish

Jawless fish reported from the Xitun Formation
GenusSpeciesPresence MaterialNotesImages
Parathelodus P. asiaticus Qilin district, Qujing.[8] Body scales.[8] A thelodont also known from the Xishancun Formation.
P. cornuformis Qilin district, Qujing.[8] Body scales.[8] A thelodont also known from the Xishancun Formation.
P. liaokuoensis Qilin district, Qujing.[8] Body scales.[8] A thelodont also known from the Xishancun Formation.
P. scitulus Qilin district, Qujing.[8] A complete body scale (IVPP V 12156.1).[8] A thelodont also known from the Xishancun Formation.
P. trilobatus Qilin district, Qujing.[8] Body scales.[8] A thelodont also found in the Xishancun Formation.
P. wangi Qilin district, Qujing.[8] Body scales.[8] A thelodont also known from the Xishancun Formation.
P. xitunensis Qilin district, Qujing.[8] A complete body scale (IVPP V 26113.1).[8] A thelodont.
Turinia T. asiatica Qujing.[3] Multiple scales.[3] A thelodont.
Xitunaspis X. magnus Qujing.[9] 4 headshields.[9] A galeaspid.

Placoderms

Placoderms reported from the Xitun Formation
GenusSpeciesPresence MaterialNotesImages
Antiarchi Unnamed antiarch Qujing.[1] MNHN-CHD02 & V10515.[1] Originally referred to ?Xichonelepis.
Asterosteidae Gen. et. sp. indet. Qujing.[10] Part of the head shield.[10] Very similar to Gemuendina.[10]
Chuchinolepis C. gracilis Qujing.[1] Detached plates.[1] A chuchinolepidid also known from the Xishancun Formation.
C. qujingensis Plates.[1] A chuchinolepidid also known from the Xishancun Formation.
C. robusta Qujing.[1] A detached AVL plate (V10512).[1] A chuchinolepidid.
C. sulcata Qujing.[1] Trunkshield, plates & incomplete pectoral fin.[1] A chuchinolepidid.
Gavinaspis G. convergens Qujing.[11] Skull remains.[11] A phyllolepid.
Parayunnanolepis P. xitunensis Almost-complete specimen.[12] A yunnanolepidid.
Phymolepis P. cuifengshanensis Cuifengshan and Liaokuoshan, Qujing.[1][13] Plates.[1][13] A yunnanolepidid also known from the Xishancun Formation.
P. guoruii Qujing.[1] Trunk-shields & plates.[1] A yunnanolepidid.
Szeaspis S. yunnanensis Qujing.[14] Neurocranium & associated skull roof (IVPP V 5810a-b).[14] Preoccupied genus name, renamed Szelepis.
Szelepis S. yunnanensis Qujing.[14] Neurocranium & associated skull roof (IVPP V 5810a-b).[14] An actinolepid originally named Szeaspis.
Yunnanolepis Y. porifera Qujing.[1] A yunnanolepidid also known from the Xishancun Formation.
Y. sp. Qujing.[1] A trunk-shield associated with part of skull roof (V10514).[1] A yunnanolepidid, specimen formerly assigned to Vanchienolepis.
Zhanjilepis Z. aspratilis Qujing.[1] Plates.[1] A yunnanolepidid also known from the Xishancun Formation.

Sarcopterygians

Sarcopterygians reported from the Xitun Formation
GenusSpeciesPresence MaterialNotesImages
Achoania A. jarvikii Qujing.[15] Anterior cranial portion.[15] A basal lobe finned fish.
Diabolepis D. speratus Xichong, Qujing.[16] Multiple specimens.[16][17] A dipteriform originally named Diabolichthys.
Psarolepis P. romeri Xichong, Qujing.[18] 4 anterior cranial portions, a posterior cranial portion, 2 complete lower jaws & an incomplete lower jaw.[18] A basal lobe finned fish.
Styloichthys S. changae Qujing.[19] Multiple specimens.[19] A basal coelacanth.[20]
Youngolepis Y. praecursor Numerous specimens.[21] A basal lobe finned fish also known from the Bac Bun Formation.

Plants

Plants reported from the Xitun Formation
GenusSpeciesPresence MaterialNotesImages
Gen. nov. A Huaguo Hill, Shengfeng district of Qujing city.[2] Numerous specimens.[2]
aff. Huia aff. H. sp. Huaguo Hill, Shengfeng district of Qujing city.[2] PKU-XH214.[2] A lycophyte.
Unnamed spike Huaguo Hill, Shengfeng district of Qujing city.[2] A poorly preserved terminal spike (PKU-XH215a, 215b).[2] Probably from a zosterophyll.
Xitunia X. spinitheca Qujing.[22] A zosterophyll.
Zosterophyllum Z. minorstachyum Qujing.[22] A zosterophyll.
Z. shengfengense A building site at Huaguo Hill, Shengfeng District, Qujing City.[23] A nearly entire individual plant preserved as a compression (PUH-QXI01-1), and its counterpart (PUH-QXI01-1’).[23] A zosterophyll.

See also

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Zhu, Min (1996-01-01). "The phylogeny of the Antiarcha (Placodermi, Pisces), with the description of Early Devonian antiarchs from Qujing, Yunnan, China". Bull. Mus. Nat. Hist. Natur., Sér.
  2. 1 2 3 4 5 6 7 8 9 10 11 Xue, Jinzhuang (March 2012). "Lochkovian plants from the Xitun Formation of Yunnan, China, and their palaeophytogeographical significance". Geological Magazine. 149 (2): 333–344. Bibcode:2012GeoM..149..333X. doi:10.1017/S001675681100077X. ISSN 0016-7568. S2CID 129280508.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Wang, Nianzhong.; Wang, Nianzhong (1984). "Thelodont, acanthodian, and chondrichthyan fossils from the Lower Devonian of southwestern China". Proceedings of the Linnean Society of New South Wales. 107: 419–441. ISSN 0370-047X.
  4. 1 2 3 4 5 6 7 8 9 10 Li, Qiang; Cui, Xindong; Andreev, Plamen Stanislavov; Zhao, Wenjin; Wang, Jianhua; Peng, Lijian; Zhu, Min (2021-05-07). "Nostolepis scale remains (stem Chondrichthyes) from the Lower Devonian of Qujing, Yunnan, China". PeerJ. 9: e11093. doi:10.7717/peerj.11093. ISSN 2167-8359. PMC 8109008. PMID 34012725.
  5. ↑ Zhu, Min. "Meemannia eos, a basal sarcopterygian fish from the Lower Devonian of China – expanded description and significance". Academia.
  6. ↑ Lu, Jing; Giles, Sam; Friedman, Matt; den Blaauwen, Jan L.; Zhu, Min (2016-06-20). "The Oldest Actinopterygian Highlights the Cryptic Early History of the Hyperdiverse Ray-Finned Fishes". Current Biology. 26 (12): 1602–1608. doi:10.1016/j.cub.2016.04.045. ISSN 0960-9822. PMID 27212403. S2CID 3928790.
  7. 1 2 Cui, Xindong; Qu, Qingming; Andreev, Plamen S.; Li, Qiang; Mai, Huijuan; Zhu, Min (2021-03-04). "Modeling scale morphogenesis in a Devonian chondrichthyan and scale growth patterns in crown gnathostomes". Journal of Vertebrate Paleontology. 41 (2): e1930018. Bibcode:2021JVPal..41E0018C. doi:10.1080/02724634.2021.1930018. ISSN 0272-4634. S2CID 237517966.
  8. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Xin-Dong, C. U. I.; Qiang, L. I.; Min, Z. H. U.; Min, Z. H. U. (2020-01-20). "New material of thelodonts from Lochkovian (Lower Devonian) of Qujing, Yunnan, China". Vertebrata PalAsiatica. 58 (1): 1. doi:10.19615/j.cnki.1000-3118.190612. ISSN 2096-9899.
  9. 1 2 Hao-Ran, Sun; Gai, Zhikun; Jia-Chen, Cai; Qiang, L I (April 2022). "Xitunaspis, a new eugaleaspid fish (Eugaleaspiformes, Galeaspida) from the Lower Devonian of Qujing, Yunnan". Vertebrata PalAsiatica. doi:10.19615/j.cnki.2096-9899.220412.
  10. 1 2 3 Jun-Qing, Wang (1991-04-19). "Discovery of asterosteidae from Lower Devonian in Eastern Yuannan". Vertebrata PalAsiatica. 29 (2): 162. ISSN 2096-9899.
  11. 1 2 Dupret, V.; Zhu, M. (30 November 2007). "The earliest phyllolepid (Placodermi, Arthrodira) from the Late Lochkovian (Early Devonian) of Yunnan (South China)". Geological Magazine. 145 (2): 257–278. doi:10.1017/S0016756807004207. ISSN 1469-5081. S2CID 129360262.
  12. ↑ Zhu, Min; Yu, Xiaobo; Choo, Brian; Wang, Junqing; Jia, Liantao (2012-06-23). "An antiarch placoderm shows that pelvic girdles arose at the root of jawed vertebrates". Biology Letters. 8 (3): 453–456. doi:10.1098/rsbl.2011.1033. PMC 3367742. PMID 22219394.
  13. 1 2 Wang, Yajing; Zhu, Min (2018-05-28). "Redescription of Phymolepis cuifengshanensis (Antiarcha: Yunnanolepididae) using high-resolution computed tomography and new insights into anatomical details of the endocranium in antiarchs". PeerJ. 6: e4808. doi:10.7717/peerj.4808. ISSN 2167-8359. PMC 5978403. PMID 29868260.
  14. 1 2 3 4 Dupret, Vincent; Zhu, Min; Wang, Jun-Qing (2017-03-04). "Redescription of Szelepis Liu, 1981 (Placodermi, Arthrodira), from the Lower Devonian of China". Journal of Vertebrate Paleontology. 37 (2): e1312422. Bibcode:2017JVPal..37E2422D. doi:10.1080/02724634.2017.1312422. ISSN 0272-4634. S2CID 90912807.
  15. 1 2 Zhu, Min; Yu, Xiaobo; Ahlberg, Per E. (2001). "A primitive sarcopterygian fish with an eyestalk". Nature. 410 (6824): 81–84. doi:10.1038/35065078. ISSN 0028-0836. PMID 11242045. S2CID 4416579.
  16. 1 2 Chang, Meemann; Yu, Xiaobo (January 1984). "Structure and phylogenetic significance of Diabolichthys speratus gen. et sp. nov., a new dipnoan-like form from the Lower Devonian of eastern Yunnan, China". Proceedings of the Linnean Society of New South Wales. 107 (3): 171–184.
  17. ↑ Chang, Meemann (January 1995). "Diabolepis and its bearing on the relationships between porolepiforms and dipnoans". Bulletin du Muséum National d'Histoire Naturelle, Section C. 17 (1): 235–268.
  18. 1 2 Yu, Xiaobo (1998). "A New Porolepiform-Like Fish, Psarolepis romeri, gen. et sp. nov. (Sarcopterygii, Osteichthyes) from the Lower Devonian of Yunnan, China". Journal of Vertebrate Paleontology. 18 (2): 261–274. Bibcode:1998JVPal..18..261Y. doi:10.1080/02724634.1998.10011055. ISSN 0272-4634. JSTOR 4523897.
  19. 1 2 Zhu, Min; Yu, Xiaobo (September 2002). "A primitive fish close to the common ancestor of tetrapods and lungfish". Nature. 418 (6899): 767–770. Bibcode:2002Natur.418..767Z. doi:10.1038/nature00871. ISSN 1476-4687. PMID 12181564. S2CID 4389974.
  20. ↑ Friedman, Matt (January 2007). "Styloichthys as the oldest coelacanth: Implications for early osteichthyan interrelationships". Journal of Systematic Palaeontology. 5 (3): 289–343. Bibcode:2007JSPal...5..289F. doi:10.1017/S1477201907002052. ISSN 1477-2019. S2CID 83712134.
  21. ↑ Cui, Xindong; Friedman, Matt; Qiao, Tuo; Yu, Yilun; Zhu, Min (2022-05-02). "The rapid evolution of lungfish durophagy". Nature Communications. 13 (1): 2390. Bibcode:2022NatCo..13.2390C. doi:10.1038/s41467-022-30091-3. ISSN 2041-1723. PMC 9061808. PMID 35501345. S2CID 248504614.
  22. 1 2 Xue, Jinzhuang (2009-06-10). "Two Zosterophyll Plants from the Lower Devonian (Lochkovian) Xitun Formation of Northeastern Yunnan, China". Acta Geologica Sinica - English Edition. 83 (3): 504–512. Bibcode:2009AcGlS..83..504X. doi:10.1111/j.1755-6724.2009.00057.x. S2CID 131021391.
  23. 1 2 Hao, Shougang; Xue, Jinzhuang; Guo, Dali; Wang, Deming (January 2010). "Earliest rooting system and root : shoot ratio from a new Zosterophyllum plant". New Phytologist. 185 (1): 217–225. doi:10.1111/j.1469-8137.2009.03056.x. ISSN 0028-646X. PMID 19825018. S2CID 5638825.


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