Short description: Geologic formation in Gansu, China
The Xiagou Formation is the middle strata of the Xinminbao Group. It is named for its type site in Xiagou, in the Changma Basin of Gansu Province, northwestern China and is considered Early Cretaceous in age. It is known outside the specialized world of Chinese geology as the site of a Lagerstätte in which the fossils were preserved of Gansus yumenensis, the earliest true modern bird.
Description
The laminated yellowish mudstones of the Xiagou Formation are the lithified remnants of varves that were laid down as extremely fine silt settled to the bottom of a tranquil freshwater lake. The result was dense anoxic bottom sediment, where the lack of bacteria slowed the processes of decay, preserving uncompressed fossils in details that include feather impressions and remnants of the webbing between the bird's toes. The age of the formation has not yet been confidently determined. The underlying Chijinpu Formation is likely the same age as the Jehol Group due to the presence of similar fossils, meaning that the Xiagou Formation is probably slightly younger than the Jehol biota, dating to around the late Aptian.[1][2]
Fossil content
The Xiagou Formation is particularly noted for its high diversity of ancient birds. These include both modern birds close to the ancestors of living species, and related lineages now entirely extinct. Other fossils from the Xiagou Formation are characteristic of an Early Cretaceous lake ecology. There are fossils of abundant fish fauna, Charophyta and ostracods.[3]
Invertebrates
Arthropods
Genus
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Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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Blattapterix[4]
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B. gansu[4]
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Cretacechorista[5]
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C. qilianshanensis[5]
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Eurycoleus[6]
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E. arcuatus, E. clypeolatus, E. dimorphocellatus, E. parvus[6]
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A carabid.
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Glottocoleus[6]
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G. lenticulata, G. stellatus[6]
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Mesoblattina[6]
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M. cretacea[6]
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Mesocoleus[6]
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M. zhonggouense[6]
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Mesotricupes[6]
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M. reticulatus[6]
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Petalocupes[6]
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P. arcus[6]
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Phyllocoleus[6]
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P. striolatus[6]
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Planocoleus[6]
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P. ensatus[6]
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Pleurocoleus[6]
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P. catenatus[6]
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Spinus[6]
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S. yumenense[6]
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Tetillopsis[6]
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T. parvula[6]
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Yumenocoleus[6]
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Y. intermedius, Y. lineatus, Y. longus[6]
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Theropods
Birds
Ornithomimosaurs
Genus
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Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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Beishanlong[14]
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B. grandis[14]
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Yujingzi Basin
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Gray-variegated beds
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"Fore and hindlimbs with partial vertebrae."[14]
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An ornithomimosaur.
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Therizinosaurs
Genus
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Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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Suzhousaurus[15]
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S. megatherioides[15]
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Yujingzi Basin
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Gray-variegated beds
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"Dorsal vertebrae, ribs and partial shoulder girdle."[15]
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A therizinosauroid.
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Tyrannosauroids
Genus
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Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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Xiongguanlong[16]
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X. baimoensis[16]
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Yujingzi Basin
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Gray-variegated beds
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"Skull without lower jaws, partial vertebrae, ilium and femur."[16]
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A tyrannosauroid.
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Cerapods
Ceratopsians
Genus
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Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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Archaeoceratops[17]
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A. yujingziensis[18]
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Yujingzi Basin
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Gray-variegated beds
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"Caudal vertebrae and a partial hindlimb."[18]
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A neoceratopsian.
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Hadrosauroids
Genus
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Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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Jintasaurus[19]
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J. meniscus[19]
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Yujingzi Basin
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Gray-variegated beds
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"Partial skull."[19]
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A hadrosauroid.
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Xuwulong[20]
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X. yueluni[20]
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Yujingzi Basin
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Gray-variegated beds
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"Articulated skeleton lacking limbs."[20]
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A hadrosauroid.
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Sauropods
Macronarians
Genus
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Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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Qiaowanlong[21]
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Q. kangxii[21]
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Yujingzi Basin
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Gray-variegated beds
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"Cervical vertebrae and right pelvic girdle."[21]
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A somphospondylan.
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Other vertebrates
Turtles
Genus
|
Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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Changmachelys[22]
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C. bohlini[22]
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Changma Basin
|
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"Nearly complete skeletons from four individuals."[22]
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A macrobaenid.
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Fish
Genus
|
Species
|
Location
|
Stratigraphic position
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Material
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Notes
|
Images
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Shuleichthys[23]
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S. brachypteryx[23]
|
|
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"Complete skeleton from four individuals."[23]
|
An osteoglossomorph.
|
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See also
References
- ↑ You, Hai-lu; Lamanna, Matthew C.; Harris, Jerald D.; Chiappe, Luis M.; O'Connor, Jingmai; Ji, Shu-an; Lü, Jun-chang; Yuan, Chong-xi et al. (2006). "A Nearly Modern Amphibious Bird from the Early Cretaceous of Northwestern China". Science 312 (5780): 1640–1643. doi:10.1126/science.1126377. PMID 16778053. Bibcode: 2006Sci...312.1640Y. https://www.researchgate.net/publication/7005790.
- ↑ You, H.; Morschhauser, E. M.; Li, D.; Dodson, P. (2018). "Introducing the Mazongshan Dinosaur Fauna". Journal of Vertebrate Paleontology 38 (sup. 1): 1−11. doi:10.1080/02724634.2017.1396995.
- ↑ Jump up to: 3.0 3.1 3.2 3.3 L. Hou and Z. Liu. 1984. A new fossil bird from Lower Cretaceous of Gansu and early evolution of birds. Scientia Sinica, series B 27(12):1296-1301
- ↑ Jump up to: 4.0 4.1 P. Vršanský. 2003. Umenocoleoidea - an amazing lineage of aberrant insects (Insecta, Blattaria). AMBA Projekty 7(1):1-32
- ↑ Jump up to: 5.0 5.1 Y. C. Hong, D. S. Yan, and D. R. Wang. 1989. Discovery of Early Cretaceous Cretacechorista gen. nov. Insecta: Mecoptera from Jiuquan basin Gansu Province. Memoirs of Beijing Natural History Museum 44:1-9
- ↑ Jump up to: 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12 6.13 6.14 6.15 6.16 6.17 6.18 6.19 6.20 6.21 6.22 6.23 Y. C. Hong. 1982. Mesozoic Fossil Insects of Jiuquan Basin in Gansu Province 1-187
- ↑ Jump up to: 7.0 7.1 7.2 Bailleul, Alida M. (20 March 2019). "An Early Cretaceous enantiornithine (Aves) preserving an unlaid egg and probable medullary bone". Nature Communications 10 (1275): 1275. doi:10.1038/s41467-019-09259-x. PMID 30894527. Bibcode: 2019NatCo..10.1275B.
- ↑ Jump up to: 8.0 8.1 8.2 8.3 8.4 8.5 "Avian skulls represent a diverse ornithuromorph fauna from the Lower Cretaceous Xiagou Formation, Gansu Province, China". Journal of Systematics and Evolution 60 (5): 1172–1198. 2021. doi:10.1111/jse.12823. https://onlinelibrary.wiley.com/doi/10.1111/jse.12823.
- ↑ Jump up to: 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 Wang, Y.; O'Connor, J. K.; Li, D.; You, H. (2013). "Previously Unrecognized Ornithuromorph Bird Diversity in the Early Cretaceous Changma Basin, Gansu Province, Northwestern China". PLOS ONE 8 (10): e77693. doi:10.1371/journal.pone.0077693. PMID 24147058. Bibcode: 2013PLoSO...877693W.
- ↑ Jump up to: 10.0 10.1 10.2 M. Wang, D. Li, J. K. O'Connor, Z. Zhou and H. You. 2015. "Second species of enantiornithine bird from the Lower Cretaceous Changma Basin, northwestern China with implications for the taxonomic diversity of the Changma avifauna". Cretaceous Research 55: 56-65
- ↑ Jump up to: 11.0 11.1 11.2 O’Connor, J. K., D.-Q. Li, M. C. Lamanna, M. Wang, J. D. Harris, J. Atterholt, and H.-L. You. 2015. "A new Early Cretaceous enantiornithine (Aves, Ornithothoraces) from northwestern China with elaborate tail ornamentation". Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1054035 https://www.tandfonline.com/doi/abs/10.1080/02724634.2015.1054035?journalCode=ujvp20
- ↑ Jump up to: 12.0 12.1 12.2 Ji, Shu-An; Atterholt, Jessie; O'Connor, Jingmai; Lamanna, Matthew; Harris, Jerry; Li, Da-Qing; You, Hai-Lu; Dodson, Peter (2011). "A new, three-dimensionally preserved enantiornithine bird (Aves: Ornithothoraces) from Gansu Province, north-western China". Zoological Journal of the Linnean Society 162 (1): 201–219. doi:10.1111/j.1096-3642.2010.00671.x.
- ↑ You et al. 2005 A new fossil bird from the Early Cretaceous of Gansu Province, northwestern China Historical Biology 17(1-4):7-14
- ↑ Jump up to: 14.0 14.1 14.2 Makovicky, Peter J.; Li, Daqing; Gao, Ke-Qin; Lewin, Matthew; Erickson, Gregory M.; Norell, Mark A. (2010). "A giant ornithomimosaur from the Early Cretaceous of China". Proceedings of the Royal Society B: Biological Sciences 277 (1679): 191–198. doi:10.1098/rspb.2009.0236. PMID 19386658.
- ↑ Jump up to: 15.0 15.1 15.2 Li, D.; Peng, C.; You, H.; Lamanna, M. C.; Harris, J. D.; Lacovara, K. J.; Zhang, J. (2007). "A Large Therizinosauroid (Dinosauria: Theropoda) from the Early Cretaceous of Northwestern China". Acta Geologica Sinica (English Edition) 81 (4): 539−549. doi:10.1111/j.1755-6724.2007.tb00977.x. ISSN 1000-9515. https://www.academia.edu/10077283.
- ↑ Jump up to: 16.0 16.1 16.2 Li, Daqing; Norell, Mark A.; Gao, Ke-Qin; Smith, Nathan D.; Makovicky, Peter J. (2009). "A longirostrine tyrannosauroid from the Early Cretaceous of China". Proceedings of the Royal Society B: Biological Sciences 277 (1679): 183–190. doi:10.1098/rspb.2009.0249. PMID 19386654.
- ↑ Dong, Z.; Azuma, Y. (1997). "On a primitive Neoceratopsian from the early Cretaceous of China". in Dong, Z.. Sino-Japanese Silk Road dinosaur expedition. China Ocean press. pp. 68–89.
- ↑ Jump up to: 18.0 18.1 You, Hai-Lu; Tanque, Kyo; Dodson, Peter (2010). "A new species of Archaeoceratops (Dinosauria: Neoceratopsia) from the Early Cretaceous of the Mazongshan area, northwestern China". New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. Bloomington and Indianapolis: Indiana University Press. pp. 59–67. ISBN 978-0-253-35358-0.
- ↑ Jump up to: 19.0 19.1 19.2 Hai-Lu You; Da-Qing Li (2009). "A new basal hadrosauriform dinosaur (Ornithischia: Iguanodontia) from the Early Cretaceous of northwestern China". Canadian Journal of Earth Sciences 46 (12): 949–957. doi:10.1139/E09-067. Bibcode: 2009CaJES..46..949Y. http://www.nrcresearchpress.com/doi/pdf/10.1139/E09-067.
- ↑ Jump up to: 20.0 20.1 20.2 You Hailu, Li Daqing and Liu Weichang (2011). "A New Hadrosauriform Dinosaur from the Early Cretaceous of Gansu Province, China". Acta Geologica Sinica 85 (1): 51–57. doi:10.1111/j.1755-6724.2011.00377.x.
- ↑ Jump up to: 21.0 21.1 21.2 You, Hai-Lu; Li, Da-Qing (22 November 2009). "The first well-preserved Early Cretaceous brachiosaurid dinosaur in Asia". Proceedings of the Royal Society B: Biological Sciences 276 (1695): 4077–4082. doi:10.1098/rspb.2009.1278. PMID 19734188.
- ↑ Jump up to: 22.0 22.1 22.2 Brinkman, D.B.; Yuan, C.-X.; Ji, Q.; Ji, D.; You, H. (2013). "A new turtle from the Xiagou Formation (Early Cretaceous) of Changma Basin, Gansu Province, P. R. China". Palaeobiodiversity and Palaeoenvironments 93 (3): 367–382. doi:10.1007/s12549-013-0113-0. https://www.researchgate.net/publication/271742886.
- ↑ Jump up to: 23.0 23.1 23.2 A. M. Murray, H. L. You, and C. Peng. 2010. A New Cretaceous Osteoglossomorph Fish from Gansu Province, China. Journal of Vertebrate Paleontology 30(2):322-332
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