Discovery of the choristodere Hyphalosaurus baitaigouensis from the Lower Cretaceous Jiufotang Formation of western Liaoning,China and its paleobiogeographic significance  

作　　者：Li-Jun Zhang Shu-An Ji Hai-Chun Zhang 

机构地区：[1]South China Sea Culture Museum,Hainan Tropical Ocean University,Sanya 572022,Hainan Province,China [2]Key Laboratory of Stratigraphy and Paleontology,Ministry of Natural Resources,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China [3]State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment,Chinese Academy of Sciences,Nanjing 210008,Jiangsu Province,China

出　　处：《Journal of Palaeogeography》2024年第3期547-562,共16页古地理学报（英文版）

基　　金：supported by the Scientific Research Foundation of Hainan Tropical Ocean University(No.RHDRC202008);Project of Hainan Province Key R&D Program(No.ZDYF2021GXJS001).

摘　　要：The water-living reptile genus Hyphalosaurus was previously discovered in the Lower Cretaceous Yixian Formation bearing the middle Jehol Biota in western Liaoning,China.Two complete skeletons of Hyphalosaurus are reported for the first time from the Jiufotang Formation bearing the late Jehol Biota at two sites in western Liaoning.They show the typical characteristics of Hyphalosaurus baitaigouensis in terms of the contact between some cranial bones and the number of cervical and dorsal vertebrae,and therefore are assigned to H.baitaigouensis.This discovery extends the stratigraphic range of this species from the Yixian Formation to the overlying Jiufotang Formation.This paper further briefly compares the main characteristics of the two skeletons,summarizes the temporal and spatial distribution of Hyphalosaurus,and discusses the palaeogeographic evolution of western Liaoning at the middle and late Jehol Biota stages based on the aquatic habits of Hyphalosaurus and the geological background of western Liaoning.The analytical results show that the volcanic downwarped lakes,with distinct geographical divisions in western Liaoning during the deposition of the Yixian Formation,had not completely disappeared till the deposition of the Jiufotang Formation.The palaeo-lake in the Fuxin-Yixian Basin underwent the process of generation,expansion and shrinkage during the depositional period of the Yixian Formation and finally merged into a large lake.The palaeo-Dalinghe River,which connected the main basins in western Liaoning during the depositional period of the Jiufotang Formation,was formed simultaneously.

关 键 词：Western liaoning Jehol biota Jiufotang formation Hyphalosaurus baitaigouensis PALAEOBIOGEOGRAPHY 

分 类 号：Q915[天文地球—古生物学与地层学] P534.53[生物学—古生物学]