Sunjiawan Formation

Sunjiawan Formation
Stratigraphic range: Early Cenomanian
~99–95 Ma
TypeGeological formation
OverliesUnconformity with Fuxin Formation
Lithology
PrimaryConglomerate
OtherSandstone, siltstone, mudstone
Location
Coordinates41°42′N 120°48′E / 41.7°N 120.8°E / 41.7; 120.8
Approximate paleocoordinates46°12′N 112°06′E / 46.2°N 112.1°E / 46.2; 112.1
RegionLiaoning
CountryChina
ExtentBeipiao Basin
Sunjiawan Formation is located in China
Sunjiawan Formation
Sunjiawan Formation (China)
Sunjiawan Formation is located in Liaoning
Sunjiawan Formation
Sunjiawan Formation (Liaoning)

The Sunjiawan Formation (simplified Chinese: 孙家湾组; traditional Chinese: 孫家灣組; pinyin: Sūnjiāwān Zǔ) is a geological formation in Liaoning, China, with strata possibly dating back to the early Late Cretaceous, specifically the Cenomanian. Dinosaur remains are among the fossils that have been recovered from the formation. It forms part of the same geological sequence as the older and underlying Yixian Formation and Jiufotang Formation. It primarily consists of variegated conglomerates with rare intercalations of thin bedded sandstones, siltstones and mudstones.

Fossil content

Remains of the following dinosaurs have been found in the formation:

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.

Dinosaurs

Ankylosaurs

Ankylosaurs of the Sunjiawan Formation
Genus Species Location Stratigraphic position Material Notes Images
Crichtonpelta C. benxiensis A partial skeleton. A ankylosaurine ankylosaurid
Crichtonsaurus C. bohlini A partial skeleton. A ankylosaurine ankylosaurid

Ornithopods

Ornithopods of the Sunjiawan Formation
Genus Species Location Stratigraphic position Material Notes Images
Hadrosauroidea Indet. Indeterminate Dental remains Different with Shuangmiaosaurus from the same stratigraphic unit
Shuangmiaosaurus S. gilmorei A partial left upper jaw and lower jaw. A styracosternan ornithopod

Sauropods

Sauropods of the Sunjiawan Formation
Genus Species Location Stratigraphic position Material Notes Images
Borealosaurus B. wimani Two caudal vertebra, humerus and isolated tooth crown A titanosaurian sauropod
Titanosauriformes Indet. Indeterminate Single tooth Provisionally attributed to Borealosaurus

Theropods

Theropods of the Sunjiawan Formation
Genus Species Location Stratigraphic position Material Notes Images
Tyrannosauroidea Indet. Indeterminate Single tooth

See also

References

  1. ↑ Xi, Dangpeng; Wan, Xiaoqiao; Li, Guobiao; Li, Gang (January 2019). "Cretaceous integrative stratigraphy and timescale of China". Science China Earth Sciences. 62 (1): 256–286. doi:10.1007/s11430-017-9262-y.
  2. ↑ Weishampel et al., 2004, pp.563-570
  3. ↑ Wang, Yaquiong; Sha, Jingeng; Pan, Yanhong; Zhang, Xiaolin (2015). "Early Cretaceous nonmarine ostracod biostratigraphy of western Liaoning area, NE China". Micropaleontology. 61 (1–2): 135–145. doi:10.47894/mpal.61.1.10.
  4. ↑ Victoria M. Arbour; Philip J. Currie (2015). "Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs". Journal of Systematic Palaeontology. 14 (5): 385–444. doi:10.1080/14772019.2015.1059985. S2CID 214625754.
  5. ↑ Junchang, Lü; Qiang, Ji; Yubo, Gao; Zhixin, Li (December 2007). "A New Species of the Ankylosaurid Dinosaur Crichtonsaurus (Ankylosauridae: Ankylosauria) from the Cretaceous of Liaoning Province, China". Acta Geologica Sinica - English Edition. 81 (6): 883–897. doi:10.1111/j.1755-6724.2007.tb01010.x.
  6. ↑ Dong, Zhi-Ming (2002). "A new armored dinosaur (Ankylosauria) from Beipiao Basin, Liaoning Province, northeastern China". Vertebrata Palasiatica. 40 (4): 276–285.
  7. 1 2 3 Yin, Ya-Lei; Xie, Fei; Zhou, Chang-Fu; Pei, Rui (3 March 2024). "Dinosaur teeth from the mid-Cretaceous Sunjiawan Formation of western Liaoning Province, China". Historical Biology. 36 (3): 631–637. doi:10.1080/08912963.2023.2179398.
  8. ↑ Hailu, You; Qiang, Ji; Jinglu, Li; Yinxian, Li (June 2003). "A New Hadrosauroid Dinosaur from the Mid‐Cretaceous of Liaoning, China". Acta Geologica Sinica - English Edition. 77 (2): 148–154. doi:10.1111/j.1755-6724.2003.tb00557.x.
  9. ↑ Hailu, You; Qiang, Ji; Lamanna, Matthew C.; Jinglu, Li; Yinxian, Li (August 2004). "A Titanosaurian Sauropod Dinosaur with Opisthocoelous Caudal Vertebrae from the Early Late Cretaceous of Liaoning Province, China". Acta Geologica Sinica - English Edition. 78 (4): 907–911. doi:10.1111/j.1755-6724.2004.tb00212.x.