First Record of Middle Eocene Elephant Ancestors’Footprints in the Gonjo Basin,East Tibet Plateau  

作　　者：Asma Tahir Huazhou Yao Junaid Khan Yangui Li He Zhao Yue Yu Tang Yuan 

机构地区：[1]Institute of Geological Survey,China University of Geosciences,Wuhan,430074,China [2]Wuhan Center,China Geological Survey,Wuhan,430205,China [3]State Key Laboratory of Geological Processes and Mineral Resources,Wuhan,430078,China [4]Chengdu Center,China Geological Survey,Chengdu,610081,China [5]Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing,100101,China

出　　处：《Journal of Earth Science》2024年第4期1224-1235,共12页地球科学学刊（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.92055212);the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan(No.GPMR202105).

摘　　要：It is the first time that the fossil footprints of a group of Middle Eocene elephant ancestors have been discovered in the Gonjo Basin,East Tibet Plateau.The Gonjo Formation is attributed to the Middle Eocene Epoch(U-Pb age=44.7±1.2 Ma)and consists mainly of purplish-red,medium-to coarse-grained sandstones,siltstones interbedded with mudstones,and conglomerates with sedimentary structures like ripple marks,rip-up clasts,and trough-cross bedding,suggesting fluvial-lacustrine systems.The group of fossil footprints has a characteristic oval-concave shape,and the toe impressions are absent.Some fossil footprints are overstepped with a pockmarked texture resembling Proboscipeda enigmatica.More than 165 fossil footprints of the group are relatively well-preserved with different diameters,which is evidence of highly social behavior and trackmakers of different ages,including calves,juveniles,adolescents,and adults.The size frequency of the fossil footprints enabled us to deduce the body mass,shoulder height,and hip-height distribution of the trackmakers that crossed the East Tibet Plateau 44.7 Ma ago.The trackmakers comprised an estimated average hip-height of 111.8 cm,an average shoulder height of 172.8 cm for males/155.9 cm for females,and an average body mass of approximately 1218.1 kg for males/907.8 kg for females.The abundance of fossil footprints reveals that in the Middle Eocene Epoch,the environment was extraordinarily conducive for the elephant ancestors to live in the East Tibet region.

关 键 词：Proboscipeda enigmatica East Tibet Plateau Gonjo Formation fossil footprints fluvial-lacustrine 

分 类 号：P534.6[天文地球—古生物学与地层学] P597.3[天文地球—地质学] Q915[生物学—古生物学]