Department Of Geology

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Author: search.filters.author.Sehgal, Ramesh Kumar

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    First report on late Miocene (Tortonian: ~ 11�10�Ma) charophyte gyrogonites from Tapar, Kachchh District, Gujarat State, western India
    (Springer Nature, 2022-09-05T00:00:00) Singh, Nongmaithem Amardas; Singh, Ningthoujam Premjit; Sharma, K. Milankumar; Patnaik, Rajeev; Tiwari, R.P.; Sehgal, Ramesh Kumar; Kumar, Vinay; Wazir, Wasim Abass; Singh, Y. Priyananda; Choudhary, Deepak
    This paper describes the first record of charophyte gyrogonites from the late Miocene (Tortonian; ~ 11�10�Ma) Tapar locality of Kachchh, Gujarat State, western India. The recovered charophyte assemblage is constituted by Chara globularis var. aspera, C. globularis var. globularis, Lychnothamnus cf. sahnii, Lychnothamnus sp. and Nitellopsis sp. In addition, the present article discusses the palaeoenvironment based on the recorded charophyte gyrogonites (this study) and previously known faunal data (mainly vertebrates) from the Tapar locality, Kutch Basin, western India. Further, considering the significant extension of the biostratigraphic range [especially the First Appearance Datum (FAD)] of fauna from the Kutch Basin (in particular from the Tapar locality), we herein make an attempt to compare biostratigraphically the faunal assemblages from Kutch with those from the Siwalik Group, north India. � 2022, Indian National Science Academy.
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    A new window to the fossil herpetofauna of India: amphibians and snakes from the Miocene localities of Kutch (Gujarat)
    (Springer Science and Business Media Deutschland GmbH, 2021-11-25T00:00:00) Singh, Ningthoujam Premjit; Patnaik, Rajeev; ?er?ansk�, Andrej; Sharma, K Milankumar; Singh, Nongmaithem Amardas; Choudhary, Deepak; Sehgal, Ramesh Kumar
    The Miocene beds of Kutch in India are well known for their mammalian assemblages including an extinct ape Sivapithecus. We here report new amphibian and snake fossils, which have been recovered from two stratigraphic levels: the older Palasava locality which is dated to the middle Miocene (~ 14�Ma), whereas the sediments of younger sites at Tappar and Pasuda representing the late Miocene (~ 11�10�Ma). The amphibian material consists only of Rana sp., Ranidae indet. and Anura indet. The snake material is much more diverse and can be allocated to several taxa: Python sp., Acrochordus dehmi, Acrochordus sp., Ahaetuliinae indet. and Alethinophidia indet. Among all these finds, the fossils of Rana sp., Ahaetuliinae indet. and Python sp. described here form the first evidence of these taxa from the Neogene of India. The ectothermic faunas are good indicators of palaeoenvironmental conditions. The ectothermic vertebrate assemblages of these Indian localities indicate a very warm, humid/wet, tropical to sub-tropical environmental conditions during the middle and late Miocene. � 2021, Senckenberg Gesellschaft f�r Naturforschung and Springer-Verlag GmbH Germany, part of Springer Nature.
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    The Miocene fossil lizards from Kutch (Gujarat), India: A rare window to the past diversity of this subcontinent
    (Cambridge University Press, 2021-09-06T00:00:00) ?er?ansk�, Andrej; Singh, Ningthoujam Premjit; Patnaik, Rajeev; Sharma, K. Milankumar; Tiwari, Raghavendra Prasad; Sehgal, Ramesh Kumar; Singh, Nongmaithem Amardas; Choudhary, Deepak
    The Miocene beds of Kutch in India are well known for their mammalian assemblages, including the extinct ape Sivapithecus, but far less is known about the fossil squamates from this area. Although India with its over 800 reptile species is recognized as one of the global biodiversity hotspots, knowledge of past diversity and paleobiogeography of squamates on this subcontinent is very limited. We here report on new lizard finds, which have been recovered from two stratigraphic levels: the older Palasava locality (dated to the middle Miocene, ca. 14 Ma) and the younger Tapar site (late Miocene, ca. 11-10 Ma). Although fragmentarily preserved, the material described here sheds important light on the composition and paleobiogeography of squamates during the Miocene in South Asia. The older Palasava locality contains cf. Uromastyx s.l. and Varanus sp., the latter representing the oldest record of this taxon in the region of India south of the Himalayas and its occurrence here suggests a mean annual temperature not less than 15�C. The material from the younger Tapar locality consists of an unidentified acrodontan lizard, here questionably placed in agamids, and a skink. The latter shows a resemblance to mabuyines, however, the fragmentary nature of the material does not allow a precise allocation without doubts. The cosmopolitan mabuyines have been suggested to have their origin in Asia, so the potential presence of mabuyines in the Tapar locality might represent the first, but putative, Asian evidence of the occurrence of this group in the Miocene. Copyright � The Author(s), 2021. Published by Cambridge University Press on behalf of The Paleontological Society.