Bhat et al.—Late Triassic freshwater sharks from India
corroborates the findings of Ray et al. (2016) and Datta et al. (2016) that the Tiki Formation may be younger than previously suggested. India is one of the three widely separated regions, including
Argentina (Johns et al., 2014) and Madagascar (Burmeister et al., 2006), from where Late Triassic freshwater hybodonts are reported. Three hybodont genera Lonchidion, Polyacrodus (Prasad et al., 2008), and Pristrisodus n. gen., (current study) are known from India, of which the latter genus is endemic. Lonchidion is known from North America (Murry, 1981; Cappetta, 2012), India (Prasad et al., 2008), and Spain (Manzaneras et al., 2016), whereas Polyacrodus is known from Germany and eastern France (Cappetta, 2012), although there are doubts regarding its validity (Rees, 2008; Cappetta, 2012). Hence, the Indian hybodont fauna shows resemblance to the European and North American forms that are known from coeval horizons. Most of these genera were euryhaline in nature (Maisey, 1989; Cuny et al., 2006), which may have resulted in their adaptation to freshwater systems in India during the Carnian. Further study is required to explain their migration along the coastlines prior to Pangaean rifting.
Acknowledgments
We thank D. Mukherjee of the Geological Studies Unit, Indian Statistical Institute, Kolkata, India for active participation during fieldwork, and critical comments on an earlier draft of the manuscript. We are grateful to C. Duffin of the Earth Science Department, Natural History Museum UK for valuable suggestions and insightful discussions during preparation of the revised draft of the manuscript. The constructive criticism and comments of two anonymous reviewers, D. J. Ward, and J. Kriwet are gratefully acknowledged. We are indebted to A. Bhaumik of the Department of Applied Geology, Indian School of Mines, Dhanbad, India, N. Bhowmik, and K. Datta for facilitating Scanning Electron Microscopy. C. Desarkar is acknowledged for thin-section preparations. Financial assis- tance and infrastructural facilities were provided by the Department of Science and Technology, India and the Indian Institute of Technology, Kharagpur, India, respectively.
Accessibility of supplemental data
Data available from the Dryad Digital Repository:
http://dx.doi. org/10.5061/
dryad.mq282
References Ansorge, J., 1990, Fischreste (Selachii, Actinopterygii) aus der Wealden- tonscholle von Lobber Ort (Mönchgut/Rügen/DDR): Paläontologische Zeitschrift, v. 64, p. 133–144.
Bandyopadhyay, S., 1999, Gondwana vertebrate faunas of India: Proceedings of the Indian National Science Academy, v. 65, p. 285–313.
Bandyopadhyay, S., 2011, Non-marine Triassic vertebrates of India, in Calvo, J.O., Porfiri, J., Gonzalez, B., and Santos, D.D., eds., Paleontología y Dinosaurios desde América Latina: EDIUNC, Editorial de la Universidad Nacional de Cuyo, Mendoza, Argentina, p. 33–46.
Becker, M.A., Chamberlain, J.A., and Terry, D.O., 2004, Chondrichthyans from the Fairpoint Member of the Fox Hills Formation (Maastrichtian), Meade County, South Dakota: Journal of Vertebrate Paleontology, v. 24, p. 780–793.
237
Bhat, M.S., 2015, A new and diverse late Triassic fish assemblage from India: International conference on current perspectives and emerging issues in Gondwana evolution, Lucknow, India, Abstract Volume, p. 22.
Bhat, M.S., 2017, Techniques for systematic collection and processing of vertebrate microfossils from their host mudrocks: a case study from the Upper Triassic Tiki Formation of India: Journal of the Geological Society of India, v. 89, p. 369–374.
Bhat, M.S., Ray, S., and Datta, P.M., 2015, Small archosauriform teeth from the Late Triassic of India: implications on early radiation of the dinosaurs:XXV Indian Colloquium on Micropaleontology and Stratigraphy, Aurangabad, India, Abstract Volume, p. 70–71.
Bhat, M.S., Ray, S., and Datta, P.M., 2017, Multivariate analyses reveal a new assemblage of diverse and small archosauriforms (Reptilia, Diapsida) from the Upper Triassic of India: Geophysical Research Abstracts Volume 19, EGU2017-18516, European Geosciences Union General Assembly 2017.
Błażejowski, B., 2004, Shark teeth from the Lower Triassic of Spitsbergen and their histology: Polish Polar Research, v. 25, p. 153–167.
Bonaparte, C.L.J., 1838, Selachorum tabula analytica: NuoviAnnali delle Scienze Naturali Bologna, v. 1, p. 195–214.
Broom, R., 1909, The fossil fishes of the Upper Karroo Beds of South Africa: Annals of South African Museum, v. 7, p. 251–269.
Burmeister, K.C., Flynn, J.J., Parrish, J.M., and Wyss, A.R., 2006, Paleogeo- graphic and biostratigraphic implications of new Early Mesozoic terrestrial vertebrate fossils from Poamay, central Morondava Basin, Madagascar, in Harris, J.D., Lucas, S.G., Spielmann, J.A., Lockley, M.G., Milner, A.R. C., and Kirkland, J.I., eds., The Triassic-Jurassic terrestrial transition: Bulletin of the New Mexico Museum of Natural History, v. 37, p. 457–475.
Cappetta, H., 1987, Chondrichthyes II: Mesozoic and Cenozoic Elasmobranchii, in Schultze, H.-P., ed., Handbook of Paleoichthyology 3B: Stuttgart, Gustav Fischer Verlag, 193 p.
Cappetta, H., 2012, Chondrichthyes: Mesozoic and Cenozoic Elasmobranchii: Teeth, in Schultze, H.-P., ed., Handbook of Paleoichthyology 3E: Munich, Verlag Dr. Friedrich Pfeil, 512 p.
Carlson, S.J., 1989, Vertebrate dental structures, in Carter, J.G., ed., Skeletal Biomineralization: Patterns, Processes and Evolutionary Trends, Vol. 1: New York, Van Nostrand Reinhold, p. 531–556.
Chinsamy, A., and Raath, M.A., 1992, Preparation of fossil bone for histological study: Palaeontologia Africana, v. 29, p. 39–44.
Cifelli, R.L., Madsen, S.K., and Larson, M.E., 1996, Techniques for recovery and preparation of microvertebrate fossils: Oklahama Geological Survey Special Publication, v. 96, p. 1–24.
Cuny, G., 2012, Freshwater hybodont shark in Early Cretaceous ecosystems: a review, in Godefroit, P., ed., Bernissart Dinosaurs and Early Cretaceous Terrestrial Ecosystems: Bloomington, Indiana University Press, p. 519–529.
Cuny, G., Suteethorn, V., Kamha, S., Buffetaut, E., and Philippe, M., 2006, Anew hybodont shark assemblage from the Lower Cretaceous of Thailand: Historical Biology, v. 18, p. 21–31.
Cuny, G., Suteethorn, V., Buffetaut, E., and Ouaja, M., 2007, Hybodont sharks from the Aptian–Albian of Tunisia and Thailand: Bulletin de la Société d’Etude des Sciences Naturelles d’Elbeuf, v. 1, p. 71–85.
Datta, D., Mukherjee, D., and Ray, S., 2016, A new phytosaur (Diapsida; Archosauria) bonebed from the Late Triassic Tiki Formation of India: taphonomic signatures: 76th Annual Meeting of the Society of Vertebrate Paleontology, Salt Lake City, Utah, Program and Abstracts, 2016, p. 123.
Datta, P.M., 1981, The first Jurassic mammal from India: Zoological Journal of the Linnean Society of London, v. 73, p. 307–312.
Datta, P.M., 2004, A suggestion for an early Tuvalian time segment for the Tiki Formation, South Rewa Gondwana Basin, India and other correlatable continental sequences: Albertina, v. 30, p. 6–7.
Datta, P.M., 2005, Earliest mammal with transversely expanded upper molar from the Late Triassic (Carnian) Tiki Formation, South Rewa Gondwana Basin, India: Journal of Vertebrate Paleontology, v. 25, p. 200–207.
Datta, P.M., Yadagiri, P., and Rao, B.R.J., 1978, Discovery of Early Jurassic micromammals from Upper Gondwana sequence of Pranhita-Godavari Valley, India: Journal of the Geological Society of India, v. 19, p. 64–68.
Datta, P.M., Das, D.P., and Luo, Z.X., 2004, A Late Triassic dromatheriid (Synapsida: Cynodontia) from India: Annals of the Carnegie Museum, v. 73, p. 72–84.
Duffin, C.J., 1985, Revision of the hybodont selachian genus Lissodus Brough (1935): Palaeontographica A, v. 188, p. 105–152.
Donath, K., 1995, Preparation of Histologic Sections: Hamburg, EXAKT– Kulzer Publication, 16 p.
Duffin, C., and Theis, D., 1997, Hybodont shark teeth from the Kimmeridgian (Late Jurassic) of northwest Germany: Geologica Palaeontologica, v. 31, p. 235–256.
Duffin, C.J., 1993, Mesozoic chondrichthyan faunas 1. Middle Norian (Upper Triassic) of Luxembourg: Palaeontographica A, v. 229, p. 15–36.
Duncan, M., 2004, Chondrichthyan genus Lissodus from the Lower Carboni- ferous of Ireland: Acta Palaeontologica Polonica, v. 49, p. 417–428.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190 |
Page 191 |
Page 192 |
Page 193 |
Page 194 |
Page 195 |
Page 196 |
Page 197 |
Page 198 |
Page 199 |
Page 200 |
Page 201 |
Page 202 |
Page 203 |
Page 204
