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Not to be confused with Hekou Group.

The Hekou Formation is a Cretaceous geologic formation in China. Pterosaur fossils have been recovered from the formation. It is a unit of the Guifeng Group and dates to the Late Cretaceous.[2] Dinosaur fossils from the formation include a nearly perfect oviraptorid embryo nicknamed Baby Yingliang, an unnamed large hadrosaurid, and hadrosauroid eggs with embryos.[3][4][5] Mammal fossils include Erythrobaatar and Yubaatar qianzhouensis.[6][7] The orientalosuchine alligatoroid Eurycephalosuchus.[8] The polyglyphanodontian lizards Xenodontolacerta and Yechilacerta has also been described from the formation.[9][10]

Description

The Hekou Formation is a constituent of the Guifeng Group; a sequence of formations that were deposited in the Xinjiang Basin including the Hekou, Tangbian, and Lianhe formation which record aeolian-alluvial interactions in a palaeoplateau desert. Both a successional and coeval model of the deposition of these units have been proposed, with estimated ages of the Hekou formation ranging from Coniacian–Santonian to Maastrichtian.[11][12]The associated facies include alluvial fans and adjacent wadi river channels, with mudcracks indicating subaerial exposure of the deposits. Oxygen-18 isotope values recorded in Dinosaur eggshells indicated low annual precipitation and humidity, suggesting an arid to semi-arid environment. The occurrence of striated cobbles in the alluvial facies suggests glacial activity in the catchment areas of the Cretaceous plateau.[13][14] Vertebrates originally interpreted as coming from the Nanxiong Formation have been reinterpreted as coming from the Hekou Formation. [15] The classification of the Guifeng Group is contentious,some authors contend the boundaries between the Hekou,Tangbian & Lianhe Formations are indistinct and that they all belong to the Hekou Formation. [16] Additionally studies have contended that the three formations to be coeval and formed at roughly the same time. [17]

See also

References

  1. ^ Xing, Lida; Niu, Kecheng; Yang, Tzu-Ruei; Wang, Donghao; Miyashita, Tetsuto; Mallon, Jordan C. (2022-05-09). “Hadrosauroid eggs and embryos from the Upper Cretaceous (Maastrichtian) of Jiangxi Province, China”. BMC Ecology and Evolution. 22 (1) 60. doi:10.1186/s12862-022-02012-x. ISSN 2730-7182. PMC 9088101. PMID 35534805.
  2. ^ 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. S2CID 135150710.
  3. ^ Xing, Lida; Niu, Kecheng; Ma, Waisum; Zelenitsky, Darla K.; Yang, Tzu-Ruei; Brusatte, Stephen L. (2022). “An exquisitely preserved in-ovo theropod dinosaur embryo sheds light on avian-like prehatching postures”. iScience. 25 (1) 103516. Bibcode:2022iSci…25j3516X. doi:10.1016/j.isci.2021.103516. PMC 8786642. PMID 35106456.
  4. ^ Xing, Lida; Niu, Kecheng; Wang, Donghao; Marquez, Albert Prieto (2020-06-18). “A partial articulated hadrosaurid skeleton from the Maastrichtian (Upper Cretaceous) of the Ganzhou area, Jiangxi Province, China”. Historical Biology. 33 (10): 2256–2259. doi:10.1080/08912963.2020.1782397. ISSN 0891-2963. S2CID 225764043.
  5. ^ Xing L, Niu K, Yang TR, Wang D, Miyashita T, Mallon JC (2022). “Hadrosauroid eggs and embryos from the Upper Cretaceous (Maastrichtian) of Jiangxi Province, China”. BMC Ecology and Evolution. 22 (1) 60. doi:10.1186/s12862-022-02012-x. PMC 9088101. PMID 35534805.
  6. ^ Jin, X.; Mao, F.; Du, T.; Yang, Y.; Meng, J. (2022). “A new multituberculate from the latest Cretaceous of central China and its implications for multituberculate tooth homologies and occlusion”. Journal of Mammalian Evolution. 30: 1–20. doi:10.1007/s10914-022-09636-2. S2CID 253192551.
  7. ^ Hu, J.; Han, F. (2021). “A new multituberculate, Yubaatar qianzhouensis sp. nov.: the first Late Cretaceous mammal from Ganzhou Basin, Jiangxi Province”. Acta Palaeontologica Sinica. 60 (4): 565–579. doi:10.19800/j.cnki.aps.2020057.
  8. ^ Wu XC, Wang YC, You HL, Zhang YQ, Yi LP (2022). “New brevirostrines (Crocodylia, Brevirostres) from the Upper Cretaceous of China”. Cretaceous Research. 144 105450. 105450. doi:10.1016/j.cretres.2022.105450. S2CID 255051769.
  9. ^ Xing, Lida; Niu, Kecheng; Evans, Susan E. (2023). “A new polyglyphanodontian lizard with a complete lower temporal bar from the Upper Cretaceous of southern China”. Journal of Systematic Palaeontology. 21 (1). Bibcode:2023JSPal..2181494X. doi:10.1080/14772019.2023.2281494. ISSN 1477-2019.
  10. ^ Jiang, Juan; Dong, Li-Ping; Xu, Xing; Bi, Alexander; Evans, Susan (2026-02-04). “A new polyglyphanodontian lizard from the Upper Cretaceous of southern China implies a complex evolutionary history of the clade”. Royal Society Open Science. 13 (2). doi:10.1098/rsos.252253. ISSN 2054-5703.
  11. ^ Xing, Lida; Niu, Kecheng; Zhang, Lijun; Yang, Tzu-Ruei; Zhang, Jianping; Persons IV, W. Scott; Romilio, Anthony; Zhuang, Yuhui; Ran, Hao (June 3, 2020). “Dinosaur Eggs Associated with Crustacean Trace Fossils from the Upper Cretaceous of Jiangxi, China: Evidence for Foraging Behavior?”. Biosis: Biological Systems: 54–59. doi:10.37819/biosis.001.002.0058. ISSN 2707-9783.
  12. ^ Xi, Dangpeng; Wan, Xiaoqiao; Li, Guobiao; Li, Gang (2019-01-01). “Cretaceous integrative stratigraphy and timescale of China”. Science China Earth Sciences. 62 (1): 256–286. doi:10.1007/s11430-017-9262-y. ISSN 1869-1897.
  13. ^ Jiao, Haijing; Wu, Chihua; Rodríguez-López, Juan Pedro; Sun, Xiaoming; Yi, Haisheng (2020-10-01). “Late Cretaceous plateau deserts in the South China Block, and Quaternary analogues; sedimentology, dune reconstruction and wind-water interactions”. Marine and Petroleum Geology. 120 104504. Bibcode:2020MarPG.12004504J. doi:10.1016/j.marpetgeo.2020.104504. ISSN 0264-8172.
  14. ^ He, Qing; Jiang, Qin; Xing, Lida; Zhang, Shukang; Pang, Wenjing; Hu, Hui; Lu, Shuo; Yin, Qifeng (2019-07-01). “Geochemical characteristics of newly discovered Elongatoolithidae eggs from the Upper Cretaceous of Jiangxi Province, southern China: Palaeoenvironmental and palaeoclimatic inferences”. Cretaceous Research. 99: 352–364. Bibcode:2019CrRes..99..352H. doi:10.1016/j.cretres.2018.12.015. ISSN 0195-6671.
  15. ^ Mao, Fangyuan (2022). “A new multituberculate from the latest Cretaceous of central China and its implications for multituberculate tooth homologies and occlusion”.
  16. ^ He, Qing; Jiang, Qin; Xing, Lida; Zhang, Shukang; Pang, Wenjing; Hu, Hui; Lu, Shuo; Yin, Qifeng (2019-07-01). “Geochemical characteristics of newly discovered Elongatoolithidae eggs from the Upper Cretaceous of Jiangxi Province, southern China: Palaeoenvironmental and palaeoclimatic inferences”. Cretaceous Research. 99: 352–364. doi:10.1016/j.cretres.2018.12.015. ISSN 0195-6671.
  17. ^ Xing, Lida; Niu, Kecheng; Ma, Waisum; Zelenitsky, Darla K.; Yang, Tzu-Ruei; Brusatte, Stephen L. (2022-01-21). “An exquisitely preserved in-ovo theropod dinosaur embryo sheds light on avian-like prehatching postures”. iScience. 25 (1). doi:10.1016/j.isci.2021.103516. ISSN 2589-0042. PMID 35106456.