New early Eocene vertebrate assemblage from western India reveals a mixed fauna of European and Gondwana affinities  

作　　者：Thierry Smith Kishor Kumar Rajendra S.Rana Annelise Folie Floreal Sole Corentin Noiret Thomas Steeman Ashok Sahni Kenneth D.Rose 

机构地区：[1]Directorate Earth and History of Life,Royal Belgian Institute of Natural Sciences,29 rue Vautier,B-1000,Brussels,Belgium [2]Wadia Institute of Himalayan Geology,33 General Mahadeo Singh Road,Dehradun,248001,Uttarakhand,India [3]Department of Geology,H.N.B.Garhwal University,Srinagar,246175,Uttarakhand,India [4]Scientific Heritage Survey,Royal Belgian Institute of Natural Sciences,29 rue Vautier,B-1000,Brussels,Belgium [5]Department of Geology,University of Namur,61 rue de Bruxelles,B-5000,Namur,Belgium [6]Research Unit Palaeontology,Ghent University,Krijgslaan 281,58,B-9000,Ghent,Belgium [7]Centre of Advanced Study in Geology,Panjab University,Chandigarh,160014,India [8]Center for Functional Anatomy and Evolution,Johns Hopkins University School of Medicine,Baltimore,MD,21205,USA

出　　处：《Geoscience Frontiers》2016年第6期969-1001,共33页地学前缘（英文版）

基　　金：The Leakey Foundation,the National Geographic Society(Grant Nos.6868-00,7938-05,8356-07,8710-09 and 8958-11 to K.D.R.);Department of Science and Technology,Government of India(ESS/23/Ves092/2000 and SR/S4/ES-254/2007 to R.S.R.);Council for Scientific and Industrial Research of India(ES Grant 560,21/EMR-II to A.S.);the Director,Wadia Institute of Himalayan Geology,Dehradun,India(to K.K.);the Federal Science Policy Office of Belgium(BELSPO BR/121/A3/Pal Eur Africa to T.S.)supported fieldwork and research;a networking project(BELSPO BL/36/fwi05 to T.S.)funded travels of two Belgian and three Indian researchers to India and Belgium,respectively,to exchange their scientific expertise

摘　　要：The Ypresian Cambay Shale Formation at Vastan and Mangrol lignite mines in Gujarat, western India, has yielded a rich vertebrate fauna with numerous taxa of European affinities. Here we report a new, approximately contemporary vertebrate assemblage from two fossiliferous layers in the nearby mine of Tadkeshwar. These layers have yielded a similar mammal fauna with the co-occurrence of the perissodactyl-like cambaytheriid Cambaytherium thewissi, the adapoid primates Marcgodinotius indicus and cf. Asiadapis cambayensis, and the hyaenodontid lndohyaenodon raoi. The presence of these species in both Vastan and Tadkeshwar mines and at different levels suggests that the deposits between the two major lignite seams represent a single land mammal age. Apart from the aforementioned species there is a new, smaller species of Cambaytherium, and a new genus and species of esthonychid tillodont. This fauna also contains the first large early Eocene vertebrates from India, including an unidentified Coryphodon-like pantodont, a dyrosaurid crocodyliform and a new giant madtsoiid snake. Among the Tadkeshwar vertebrates several taxa are of Gondwana affinities, such as Pelomedusoides turtles, dyr- osaurids, and large madtsoiids, attesting that the early Eocene was a crucial period in India during which Laurasian taxa of European affinities co-existed with relict taxa from Gondwana before the India-Asia collision. Our results suggest that terrestrial faunas could have dispersed to or from Europe during episodes of contact between the Indian subcontinent and different island blocks along the northern margin of the Neotethys, such as the Kohistan Ladakh island-arc system. Gondwana taxa might represent remnants of ghost lineages shared with Madagascar, which reached the Indian subcontinent during the late Cretaceous; alternatively they might have come from North Africa and passed along the southern margin of the Neotethys to reach the Indian subcontinent. These dispersals would have been possible as a result of favourable paleogeographThe Ypresian Cambay Shale Formation at Vastan and Mangrol lignite mines in Gujarat, western India, has yielded a rich vertebrate fauna with numerous taxa of European affinities. Here we report a new, approximately contemporary vertebrate assemblage from two fossiliferous layers in the nearby mine of Tadkeshwar. These layers have yielded a similar mammal fauna with the co-occurrence of the perissodactyl-like cambaytheriid Cambaytherium thewissi, the adapoid primates Marcgodinotius indicus and cf. Asiadapis cambayensis, and the hyaenodontid lndohyaenodon raoi. The presence of these species in both Vastan and Tadkeshwar mines and at different levels suggests that the deposits between the two major lignite seams represent a single land mammal age. Apart from the aforementioned species there is a new, smaller species of Cambaytherium, and a new genus and species of esthonychid tillodont. This fauna also contains the first large early Eocene vertebrates from India, including an unidentified Coryphodon-like pantodont, a dyrosaurid crocodyliform and a new giant madtsoiid snake. Among the Tadkeshwar vertebrates several taxa are of Gondwana affinities, such as Pelomedusoides turtles, dyr- osaurids, and large madtsoiids, attesting that the early Eocene was a crucial period in India during which Laurasian taxa of European affinities co-existed with relict taxa from Gondwana before the India-Asia collision. Our results suggest that terrestrial faunas could have dispersed to or from Europe during episodes of contact between the Indian subcontinent and different island blocks along the northern margin of the Neotethys, such as the Kohistan Ladakh island-arc system. Gondwana taxa might represent remnants of ghost lineages shared with Madagascar, which reached the Indian subcontinent during the late Cretaceous; alternatively they might have come from North Africa and passed along the southern margin of the Neotethys to reach the Indian subcontinent. These dispersals would have been possible as a result of favourable paleogeograph

关 键 词：Vertebrates Snakes Mammals Primates Cambay Shale Formation Ypresian 

分 类 号：Q915[天文地球—古生物学与地层学]