Geology - Research Publications

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    Chondrichthyan and osteichthyan fauna from the middle Miocene deposits of Palasava, Kutch, India: implication for paleoenvironment and paleobiogeography; [Faune de chondrichtyens et d�ost�ichtyens provenant des d�p�ts du Mioc�ne moyen de Palasava, Kutch, Inde: implication pour le pal�oenvironnement et la pal�obiog�ographie]
    (Academie des sciences, 2022-12-13T00:00:00) Singh, Nongmaithem Amardas; Choudhary, Deepak; Singh, Y. Priyananda; Singh, Ningthoujam Premjit; Patnaik, Rajeev; Tiwari, R.P.; Sharma, K. Milankumar
    The Neogene of Kutch, India is well known for its rich marine and terrestrial vertebrate assemblages. However, the data of piscean fauna from the middle Miocene of India is very scarce. We report here additional chondrichthyan and osteichthyan remains from the middle Miocene deposit of Chhasra Formation, Palasava site, Kutch, Gujarat, India. The elasmobranchs include Carcharhinus Blainville, 1816 (C. brevipinna (M�ller & Henle, 1839), C. falciformis (M�ller & Henle, 1839), C. cf. leucas, C. aff. perezi, Carcharhinus sp.), Negaprion Whitley, 1940 (Negaprion sp.), Aetobatus Blainville, 1816 (Aetobatus sp.), Myliobatis Cuvier, 1816 (Myliobatis sp.), Dasyatis Rafinesque, 1810 (D. probsti Cappetta, 1970, D. rugosa Probst, 1877), Himantura M�ller & Henle, 1837 (H. menoni Sahni & Mehrotra, 1981), Pastinachus R�ppell, 1829 (Pastinachus sp.), and Taeniurops Garman, 1913 (Taeniurops sp.). The teleosts of Palasava are represented by four families including Bagridae Bleeker, 1858, Channidae Fowler, 1934, Characidae Latreille, 1925 and Cyprinidae Cuvier, 1817. S�rensen-Dice coefficient data of Palasava elasmobranchs show a good similarity index with their counterparts in the Mediterranean Sea suggesting the existence of short-lived reopening of the marine pathway. However, a much higher faunal affinity with those of Eastern Pacific indicates a gradual shift in migration path through the Pacific Ocean to Indo-Pacific region after the permanent landbridge was formed. The vertebrate fauna from the Palasava suggests a coastal, marginal marine, near-shore littoral to neritic environment of deposition with the influence of freshwater riverine system. The integration of the floras and faunas from Palasava locality indicates the presence of warm, humid/ wet, tropical to sub-tropical environmental conditions during the middle Miocene. � 2022 Elsevier Masson SAS. All rights reserved.
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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.
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    Sharks and rays (chondrichthyes, elasmobranchii) from the miocene sediments of Kutch, Gujarat, India: paleoenvironmental and paleobiogeographic implications
    (Taylor and Francis Ltd., 2021-03-05T00:00:00) Sharma, K Milankumar; Singh, N Amardas; Patnaik, Rajeev; Tiwari, R.P.; Singh, Ningthoujam Premjit; Singh, Y Priyananda; Choudhary, Deepak; Lalotra, Sushil Kumar
    We report here a diverse assemblage of sharks and batoids representing the genera Carcharhinus, Rhizoprionodon, Galeocerdo, Sphyrna, Myliobatis, Aetobatus, Dasyatis, Pastinachus, Himantura and Pristis from Tapar and Jangadia the two late and early Miocene sites, respectively, of Kutch (Gujarat, India). The shark Rhizoprionodon and batoids, Dasyatis rugosa, D. cf. probsti, Dasyatis sp., Pastinachus and Himantura are being reported for the first time from the Miocene of western coast of India. The presence of Carcharhinus sp., Rhizoprionodon sp., Lamna sp., Negaprion sp., Sphyrna lewini, Myliobatis sp., Aetobatus sp. in the early Miocene Khari Nadi Formation exposed at Jangadia suggest existence of lagoonal, near shore to outer shelf environment. The rich batoid assemblage at the Late Miocene hominoid (Sivapithecus) bearing site of Tapar indicates the presence of a fresh to brackish water environmental condition. The faunal similarity of Miocene chondrichthyan of Indian Ocean and the Mediterranean Sea regions has been assessed using the beta diversity (S�rensen�Dice coefficient) data. The early Miocene elasmobranchs from Kutch shows close affinities with those from Mediterranean Sea. Similarly, in the Indian Ocean region Miocene fauna of Kutch shows close similarity with those of Baripada Beds, Orissa, Bhuban Formation of Mizoram, Gogha Coast, Piram Island and Madagascar. � 2021 Informa UK Limited, trading as Taylor & Francis Group.