Hekou Group

The Hekou Group is a geological group in Gansu Province, China. It is Early Cretaceous in age. Many dinosaur fossils have been recovered from the Hekou Group, including iguanodonts, large sauropods, and armored dinosaurs. Fossil eggs are rare, but one oogenus, Polyclonoolithus, was discovered in the Hekou Group.^[2] Extensive fossil tracks belonging to pterosaurs and dinosaurs have also been described.^[3][4] The group spans the Valanginian to Albian and can be subdivided into four formations.^[1]

Hekou Group
Stratigraphic range: Early Cretaceous,[1] Valanginian–Albian PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geologic group
Sub-units	Huazhuang Formation, Hongkoucheng Formation, Yanguoxia Formation, Zhujiatai Formation
Underlies	Unconformity: Minhe Formation
Overlies	Unconformity: Xiangtang Formation
Thickness	3,700 m (12,100 ft)
Lithology
Primary	Sandstone, mudstone, conglomerate
Location
Coordinates	35.9°N 103.3°E / 35.9; 103.3
Approximate paleocoordinates	34.8°N 103.1°E / 34.8; 103.1
Region	Gansu
Country	China
Extent	Longzhong Basin
Hekou Group (China) Show map of China Hekou Group (Gansu) Show map of Gansu

Vertebrate paleofauna

Dinosaurs

Saurischians

Genus	Species	Region	Material	Notes	Images
Daxiatitan	D. binglingi	Upper; Lanzhou-Minhe Basin[5]	A partial skeleton including cervical, dorsal, and caudal vertebrae, ribs, and a haemal arch, scapulocoracoid, and femur	A large titanosauriform sauropod
Huanghetitan	H. liujiaxiaensis	Upper; Lanzhou-Minhe Basin[5]	A partial skeleton including caudal vertebrae, a partial sacrum and ribs, and the left shoulder girdle	A large titanosauriform sauropod
Yongjinglong[5]	Y. datangi	Upper; Lanzhou-Minhe Basin	A partial skeleton including teeth, cervical and dorsal vertebrae, a rib, the left scapulocoracoid, and the right ulna and radius	A euhelopodid titanosauriform sauropod[6]

Ornithischians

Genus	Species	Region	Material	Notes	Images
Lanzhousaurus[7]	L. magnidens		A partial skeleton including the mandible, maxillary teeth, dentary teeth, cervical and dorsal vertebrae, sternal plates, ribs, and pubes	A large styracosternan iguanodontian
Stegosaurus[8]	S. sp.	Upper member; Lanzhou-Minhe Basin	A partial skeleton including cervical and dorsal vertebrae, ribs, a right forelimb (including a partial humerus, ulna, and radius), and one dermal plate	A stegosaur distinct from Wuerhosaurus and Stegosaurus stenops. Likely contemporary with Taohelong.
Taohelong[9]	T. jinchengensis	Upper member; Lanzhou-Minhe Basin	A partial skeleton including ribs, a left ilium, a caudal vertebra, and part of the sacral shield	A nodosaurid ankylosaur, originally described as the first Asian member of the Polacanthinae

Fish

Genus	Species	Region	Material	Notes	Images
Sinamia[10]	S. lanshoensis	Middle–Lower subgroup; "fish quarry"	Many well-preserved specimens as part and counterpart fossils	A sinamiid amiiform fish

References

1. Xi, D.; Wan, X.; Li, G.; Li, G. (2018). "Cretaceous integrative stratigraphy and timescale of China". Science China Earth Sciences. 61: 1–31. doi:10.1007/s11430-017-9262-y.
2. Xie, J.-F., Zhang, S.-K., Jin, X.-S., Li, D.-Q., and Zhou, L.-Q. (2016) "A new type of dinosaur eggs from Early Cretaceous of Gansu Province, China. Archived 2016-01-29 at the Wayback Machine" Vertebrata PalAsiatica, 54(1):1-10.
3. Lockley, M.; Harris, J.D.; and Mitchell, L. 2008. "A global overview of pterosaur ichnology: tracksite distribution in space and time." Zitteliana. B28. p. 187-198. ISSN 1612-4138.
4. Li, Dawing; Azuma, Yoichi; Fujita, Masato; Lee, Yuong-Nam; Arakawa, Yohei (2006). "A preliminary report on two new vertebrae track sites including dinosaurs from the Early Cretaceous Hekou Group, Gansu Province, china". Journal of the Paleontological Society of Korea. 22 (1): 29–49.
5. Li, L. G.; Li, D. Q.; You, H. L.; Dodson, P. (2014). Butler, Richard J (ed.). "A New Titanosaurian Sauropod from the Hekou Group (Lower Cretaceous) of the Lanzhou-Minhe Basin, Gansu Province, China". PLOS ONE. 9 (1): e85979. Bibcode:2014PLoSO...985979L. doi:10.1371/journal.pone.0085979. PMC 3906019. PMID 24489684.
6. Mannion, P.D.; Upchurch, P.; Jin, X.; Zheng, W. (2019). "New information on the Cretaceous sauropod dinosaurs of Zhejiang Province, China: impact on Laurasian titanosauriform phylogeny and biogeography". Royal Society Open Science. 6 (8): 191057. Bibcode:2019RSOS....691057M. doi:10.1098/rsos.191057. PMC 6731702. PMID 31598266.
7. You, Hailu; Ji, Qiang; Li, Daqing (2005). "Lanzhousaurus magnidens gen. et sp. nov. from Gansu Province, China: the largest-toothed herbivorous dinosaur in the world" [中国甘肃发现世界上最大牙齿的植食性恐龙：巨齿兰州龙（新属、新种)]. Geological Bulletin of China. 24 (9): 785–794. ISSN 1671-2552.
8. Li, Ning; Li, Daqing; Peng, Guangzhao; You, Hailu (2024). "The first stegosaurian dinosaur from Gansu Province, China". Cretaceous Research. 158 (in press). 105852. Bibcode:2024CrRes.15805852L. doi:10.1016/j.cretres.2024.105852.
9. Yang J.-T.; You H.-L.; Li D.-Q.; Kong D.-L. (2013). "First discovery of polacanthine ankylosaur dinosaur in Asia" (PDF). Vertebrata PalAsiatica (in Chinese and English). 51 (4): 265–277.
10. Peng, Cuo; Murray, Alison M.; Brinkman, Donald B.; Zhang, Jiang-Yong; You, Hai-Lu (2015-03-04). "A new species of Sinamia (Amiiformes, Sinamiidae) from the Early Cretaceous of Lanzhou Basin, Gansu, China". Journal of Vertebrate Paleontology. 35 (2): e902847. Bibcode:2015JVPal..35E2847P. doi:10.1080/02724634.2014.902847. ISSN 0272-4634.

See also

• List of fossil sites
• List of dinosaur bearing rock formations