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Fossil snakes from the Eocene of India: new material with comments on phylogenetic relations and biogeographic and paleoecological implications

Published online by Cambridge University Press:  23 July 2025

Debajit Datta Open the ORCID record for Debajit Datta [Opens in a new window]  and
Sunil Bajpai Open the ORCID record for Sunil Bajpai [Opens in a new window]
Debajit Datta*
Affiliation:
Department of Earth Sciences, https://ror.org/00582g326 Indian Institute of Technology Roorkee , Roorkee, Uttarakhand 247667, India
Sunil Bajpai*
Affiliation:
Department of Earth Sciences, https://ror.org/00582g326 Indian Institute of Technology Roorkee , Roorkee, Uttarakhand 247667, India
*
Corresponding authors: Debajit Datta and Sunil Bajpai; Emails: debajitdatta9@gmail.com; sunil.bajpai@es.iitr.ac.in; debajitdatta.pd@es.iitr.ac.in
Corresponding authors: Debajit Datta and Sunil Bajpai; Emails: debajitdatta9@gmail.com; sunil.bajpai@es.iitr.ac.in; debajitdatta.pd@es.iitr.ac.in
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Abstract

Eocene snakes of India have the potential to shed light on the nature of snake diversification on the subcontinent following the Deccan volcanism at the Cretaceous-Paleogene boundary (K-Pg), when India was still a northward-drifting isolated landmass prior to its collision with Asia. Here, we report a diverse snake fauna from the Eocene of Kutch, western India. The fauna, dominated by aquatic forms, includes palaeophiids, a giant madtsoiid, and a possible nigerophiid. The palaeophiids from the middle Eocene (late Lutetian) comprise ?Palaeophis Owen, 1841 and Pterosphenus rannensis n. sp. Together, these taxa enrich the record of fossil snakes in the poorly known late Lutetian of India and represent the youngest record of Palaeophiidae from the Indian subcontinent. Pterosphenus rannensis n. sp. shows intermediate morphology between Palaeophis and Pterosphenus-grade snakes and is phylogenetically the earliest-diverging member of Pterosphenus Lucas, 1898. Additionally, the middle Eocene Pterosphenus biswasi Rage et al., 2003 is reassessed and retained as a valid taxon based on pterapophyseal morphology and overall form. Biogeographic considerations highlight the importance of the Indian fossil record in understanding the origin and diversification of the genus Pterosphenus. The prevalence of niche partitioning is suggested for the palaeophiids, with Pterosphenus rannensis n. sp. recovered from a tidal setting and ?Palaeophis sp. indet. from a marsh/swamp setting. The new Indian madtsoiid from the middle Eocene (early Lutetian) represents a sympatric taxon with the terrestrial/semiaquatic giant Vasuki indicus Datta and Bajpai, 2024 coexisting in a back-swamp marsh setting. The early Eocene (Ypresian) nigerophiid is among the oldest Cenozoic occurrences of this family globally.

UUID: http://zoobank.org/dc529074-73a6-4869-9b49-44caf9e2d956

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Journal of Paleontology , First View , pp. 1 - 27
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Footnotes

Handling Editor: Hans-Dieter Sues

References

Agrawal, S., Verma, P., Rao, M.R., Garg, R., Kapur, V.V., and Bajpai, S., 2017, Lignite deposits of the Kutch Basin, western India: carbon isotopic and palynological signatures of the early Eocene hyperthermal event ETM2: Journal of Asian Earth Sciences, v. 146, p. 296–303, https://doi.org/10.1016/j.jseaes.2017.04.030CrossRefGoogle Scholar
Andrews, C.W., 1901, Preliminary notes on some recently discovered extinct vertebrates from Egypt (part 2): Geological Magazine, v. 8, p. 436–444.10.1017/S0016756800179750CrossRefGoogle Scholar
Andrews, C.W., 1924, Note on some ophidian vertebrae from Nigeria: Geological Survey of Nigeria, v. 7, p. 39–43.Google Scholar
Aniny, F., Georgalis, G.L., Gingerich, P.D., and Zouhri, S., 2024, Occurrence of the large aquatic snake Palaeophis cf. africanus (Serpentes, Palaeophiidae) in the middle Eocene of the Sabkha El Breij, southwestern Morocco: Historical Biology, v. 37, no. 4, p. 1−6, https://doi.org/10.1080/08912963.2024.2352863Google Scholar
Arambourg, C., 1952, Les vertébrés fossiles des gisements de phosphates (Maroc-Algérie-Tunisie): Notes et Mémoires du Protectorat de la République Française au Maroc, Direction de la Production Industrielle et des Mines, Division des Mines et de la Géologie, Service Géologique du Maroc, v. 92, p. 1–372.Google Scholar
Auffenberg, W., 1961, Additional remarks on the evolution of trunk musculature in snakes: American Midland Naturalist, v. 65, p. 1–16.10.2307/2422998CrossRefGoogle Scholar
Averianov, A.O., 1997, Paleogene sea snakes from the eastern part of Tethys: Russian Journal of Herpetology, v. 4, p. 128–142.10.30906/1026-2296-1997-4-2-128-142CrossRefGoogle Scholar
Averianov, A.O., 2023, Pterosphenus muruntau—valid species of sea snakes (Squamata: Palaeophiidae) from the middle Eocene of Uzbekistan: Zoosystematica Rossica, v. 32, p. 85–92, https://doi.org/10.31610/zsr/2023.32.1.85CrossRefGoogle Scholar
Bajpai, S., and Head, J.J., 2007, An early Eocene palaeopheid snake from Vastan Lignite Mine, Gujarat, India: Gondwana Geological Magazine, v. 22, p. 85–90.Google Scholar
Bajpai, S., and Thewissen, J.G.M, 2000, A new diminutive Eocene whale from Kachchh (Gujarat, India) and its implications for locomotor evolution of cetaceans: Current Science, v. 79, p. 1478–1482.Google Scholar
Bajpai, S., and Thewissen, J.G.M., 2002, Vertebrate fauna from Panandhro lignite field (lower Eocene), District Kachchh, western India: Current Science, v. 82, p. 507–509.Google Scholar
Bajpai, S. and Thewissen, J.G.M., 2014, Protocetid cetaceans (Mammalia) from the Eocene of India: Palaeontologia Electronica, v. 17, n. 3.34A, https://doi.org/10.26879/459Google Scholar
Bajpai, S., Thewissen, J.G.M., Kapur, V.V., Tiwari, B.N., and Sahni, A., 2006, Eocene and Oligocene sirenians (Mammalia) from Kachchh, India: Journal of Vertebrate Paleontology, v. 26, p. 400–410, https://doi.org/10.1671/0272-4634(2002)022[0861:EPSOTC]2.0.CO;2CrossRefGoogle Scholar
Bajpai, S., Thewissen, J.G.M., and Conley, R.W., 2011, Cranial anatomy of middle Eocene Remingtonocetus (Cetacea, Mammalia) from Kutch, India: Journal of Paleontology, v. 85, p. 703–703.10.1666/10-128.1CrossRefGoogle Scholar
Banerjee, S., Das, S., Halder, K., and Chakrabarti, N., 2019, Palaeoecological analysis of benthic molluscs from the Eocene of Kutch, Gujarat reveals an event of storm induced concentration of shells in a quiet marginal marine environment: Journal of the Geological Society of India, v. 94, p. 162–170.10.1007/s12594-019-1285-7CrossRefGoogle Scholar
Biswas, S.K., 1992, Tertiary stratigraphy of Kutch: Journal of the Palaeontological Society of India, v. 37, p. 1–29.10.1177/0971102319920101CrossRefGoogle Scholar
Caldwell, M.W., and Albino, A., 2003, Exceptionally preserved skeletons of the Cretaceous snake Dinilysia patagonica Woodward, 1901: Journal of Vertebrate Paleontology, v. 22, p. 861–866, https://doi.org/10.1671/0272-4634(2002)022[0861:EPSOTC]2.0.CO;2CrossRefGoogle Scholar
Calvert, C.J., Mead, A.J., and Parmley, D., 2022, Size estimates of the extinct marine snake Pterosphenus schucherti from Eocene-aged sediments of central Georgia: Georgia Journal of Science, v. 80, article 1, https://digitalcommons.gaacademy.org/gjs/vol80/iss2/1Google Scholar
Catuneanu, O., and Dave, A., 2017, Cenozoic sequence stratigraphy of the Kachchh Basin, India: Marine and Petroleum Geology, v. 86, p. 1106–1132, https://doi.org/10.1016/j.marpetgeo.2017.07.020CrossRefGoogle Scholar
Chatterjee, S., Scotese, C.R., and Bajpai, S., 2017, The restless Indian plate and its epic voyage from Gondwana to Asia: its tectonic, paleoclimatic, and paleobiogeographic evolution: Geological Society of America Special Paper, v. 529, p. 1–147, https://doi.org/10.1130/SPE529Google Scholar
Cope, E.D., 1868, On new species of extinct reptiles: Proceedings of the Academy of Natural Sciences of Philadelphia, v. 20, p. 250–266.Google Scholar
Cuvier, G., 1816, Le Règne Animal Distribué d’après son Organisation pour Servir de Base à l’Histoire Naturelle des Animaux et d’Introduction à l’Anatomie Compare: les Reptiles, les Poissons, les Mollusques et les Annelids: Paris, Déterville, 532 p.Google Scholar
Cuvier, G., and Valenciennes, A., 1840, Histoire naturelle des poisons, tome quinzième, suite du livre dix‑septième: Siluroïdes, v. 15, p. 1–540.Google Scholar
Datta, D., and Bajpai, S., 2024, Largest known madtsoiid snake from warm Eocene period of India suggests intercontinental Gondwana dispersal: Scientific Reports, v. 14, n. 8054, https://doi.org/10.1038/s41598-024-58377-0CrossRefGoogle ScholarPubMed
Datta, D., Mukherjee, D., and Ray, S., 2020, Taphonomic signatures of a new Upper Triassic phytosaur (Diapsida, Archosauria) bonebed from India: aggregation of a juvenile-dominated paleocommunity: Journal of Vertebrate Paleontology, v. 39, n. e1726361, https://doi.org/10.1080/02724634.2019.1726361CrossRefGoogle Scholar
Erickson, B.R., 1998, A palaeophid snake from the late Paleocene of South Carolina: Transactions of the American Philosophical Society, new ser., v. 88, no. 4, p. 215–220.10.2307/1006675CrossRefGoogle Scholar
Folie, A., Mees, F., De Putter, T., and Smith, T., 2021, Presence of the large aquatic snake Palaeophis africanus in the middle Eocene marine margin of the Congo Basin, Cabinda, Angola: Geobios, v. 66/67, p. 45–54, https://doi.org/10.1016/j.geobios.2020.11.002Google Scholar
Garberoglio, F.F., Gómez, R.O., and Caldwell, M.W., 2024, New record of aquatic snakes (Squamata, Palaeophiidae) from the Paleocene of South America: Journal of Vertebrate Paleontology, v. 43, n. e2305892, https://doi.org/10.1080/02724634.2024.2305892CrossRefGoogle Scholar
Gayet, M., Rage, J.C., and Rana, R.S., 1984, Nouvelles ichthyofaune et herpétofaune de Gitti Khadan, le plus ancien gisement connu du Deccan (Crétacé/Paléocène) à microvertébrés: implications paléogéographiques, in Buffetaut, E., Jaeger, J.J., and Rage, J.C., eds., Paléogéographie de l’Inde, du Tibet et du Sud-Est Asiatique, Confrontation des Données Paléontologiques avec les Modèles Géodynamiques, Table Ronde, Société Géologique de France et Centre National de la Recherche Scientifique, Paris, 17−20 October 1983: Paris, La Société Géologique de France, p. 55–65.Google Scholar
Georgalis, G.L., 2023, First potential occurrence of the large aquatic snake Pterosphenus (Serpentes, Palaeophiidae) from Nigeria, with further documentation of Pterosphenus schweinfurthi from Egypt: Alcheringa: An Australasian Journal of Palaeontology, v. 47, p. 327–335, https://doi.org/10.1080/03115518.2023.2217874CrossRefGoogle Scholar
Georgalis, G.L., and Smith, K.T., 2020, Constrictores Oppel, 1811—the available name for the taxonomic group uniting boas and pythons: Vertebrate Zoology, v. 70, p. 291–304, https://doi.org/10.26049/VZ70-3-2020-03Google Scholar
Georgalis, G.L., Del Favero, L., and Delfino, M., 2020, Italy’s largest snake-redescription of Palaeophis oweni (Serpentes, Palaeophiidae) from the Eocene of Monte Duello, near Verona: Acta Palaeontologica Polonica, v. 65, p. 523–533, https://doi.org/10.4202/app.00711.2019CrossRefGoogle Scholar
Georgalis, G.L., Guinot, G., Kassegne, K.E., Amoudji, Y.Z., Johnson, A.K.C., Cappetta, H., and Hautier, L., 2021a, An assemblage of giant aquatic snakes (Serpentes, Palaeophiidae) from the Eocene of Togo: Swiss Journal of Palaeontology, v. 140, n. 20, https://doi.org/10.1186/s13358-021-00236-wCrossRefGoogle Scholar
Georgalis, G.L., Rabi, M., and Smith, K.T., 2021b, Taxonomic revision of the snakes of the genera Palaeopython and Paleryx (Serpentes, Constrictores) from the Paleogene of Europe: Swiss Journal of Palaeontology, v. 140, p. 1–140, https://doi.org/10.1186/s13358-021-00224-0CrossRefGoogle Scholar
Goloboff, P.A., and Morales, M.E., 2023, TNT version 1.6, with a graphical interface for MacOS and Linux, including new routines in parallel: Cladistics, v. 39, p. 144–153, https://doi.org/10.1111/cla.12524CrossRefGoogle ScholarPubMed
Hammer, Ø., and Harper, D.A.T., 2006, Paleontological Data Analysis: Malden, Massachusetts, Blackwell 704 Publishing, 351 p.Google Scholar
Head, J.J., Holroyd, P.A., Hutchison, J.H., and Ciochon, R.L., 2005, First report of snakes (Serpentes) from the late middle Eocene Pondaung Formation, Myanmar: Journal of Vertebrate Paleontology, v. 25, p. 246–250, https://doi.org/10.1671/0272-4634(2005)025[0246:FROSSF]2.0.CO;2CrossRefGoogle Scholar
Head, J.J., Howard, A.F.C., and Müller, J., 2022, The first 80 million years of snake evolution: the Mesozoic fossil record of snakes and its implications for origin hypotheses, biogeography, and mass extinction, in Gower, D., and Zaher, H., eds., The Origin and Early Evolution of Snakes: Cambridge, UK, Cambridge University Press, p. 26–54.10.1017/9781108938891.005CrossRefGoogle Scholar
Hecht, M.K., Kropach, C., and Hecht, B.M., 1974, Distribution of the yellow-bellied sea snake, Pelamis platurus, and its significance in relation to the fossil record: Herpetologica, v. 30, p. 387–396.Google Scholar
Hoffstetter, R., 1958, Un serpent marin du genre Pterosphenus (Pterosphenus sheppardi nov. sp.) dans l’Éocène supérieur de l’Equateur (Amérique du Sud): Bulletin de la Société Geologique de France, v. 8, p. 45–50.10.2113/gssgfbull.S6-VIII.1.45CrossRefGoogle Scholar
Hoffstetter, R., 1961, Noveaux restes d’un serpent Boidé (Madtsoia madagascariensis nov. sp.) dans le Crétacé Supérieur de Madagascar: Bulletin du Muséum National d’Histoire Naturelle, sér. 2, v. 33, p. 152–160.Google Scholar
Holman, J.A., 1977, Upper Eocene snakes (Reptilia, Serpentes) from Georgia: Journal of Herpetology, v. 11, p. 141–145.10.2307/1563134CrossRefGoogle Scholar
Holman, J.A., 1982, Palaeophis casei, new species, a tiny palaeophiid snake from the early Eocene of Mississippi: Journal of Vertebrate Paleontology, v. 2, p. 163–166.10.1080/02724634.1982.10011927CrossRefGoogle Scholar
Houssaye, A., Rage, J.C., Bardet, N., Vincent, P., Amaghzaz, M., and Meslouh, S., 2013, New highlights about the enigmatic marine snake Palaeophis maghrebianus (Palaeophiidae; Palaeophiinae) from the Ypresian (lower Eocene) phosphates of Morocco: Palaeontology, v. 56, p. 647–661, https://doi.org/10.1111/pala.12008CrossRefGoogle Scholar
Hutchison, J.H., 1985, Pterosphenus cf. P. schucherti Lucas (Serpentes, Palaeophidae) from the late Eocene of peninsular Florida: Journal of Vertebrate Paleontology, v. 5, p. 20–23.10.1080/02724634.1985.10011843CrossRefGoogle Scholar
Jain, S.L., and Sahni, A., 1983, Some Upper Cretaceous vertebrates from central India and their paleogeographic implications, in Maheshwari, H.K., ed., Cretaceous of India, Proceedings of the Symposium Cretaceous of India: Palaeoecology, Palaeogeography and Time Boundaries, Lucknow, November 24−26, 1982: Lucknow, Indian Association of Palynostratigraphers, p. 66–83.Google Scholar
Janensch, W., 1906, Über Archaeophis proavus Mass., eine Schlange aus dem Eocän des Monte Bolca: Beiträge zur Paläontologie und Geologie Östreich-Ungarns und des Orients, v. 19, p. 1–33.Google Scholar
Johnson, R.G., 1955, The adaptive and phylogenetic significance of vertebral form in snakes: Evolution, v. 9, p. 367–388.10.2307/2405473CrossRefGoogle Scholar
Keller, G., Khozyem, H., Saravanan, N., Adatte, T., Bajpai, S., and Spangenberg, J., 2013, Biostratigraphy and foraminiferal paleoecology of the early Eocene Naredi Formation, SW Kutch, India: Geological Society of India Special Publication, v. 1, p. 183–196.Google Scholar
Khozyem, H., Adatte, T., Keller, G., Spangenberg, J.E., Saravanan, N., and Bajpai, S., 2013, Paleoclimate and paleoenvironment of the Naredi Formation (early Eocene), Kutch, Gujarat, India: Geological Society of India Special Publication, v. 1, p. 165–182.Google Scholar
Kumar, K., and Sahni, A., 1986, Remingtonocetus harudiensis, new combination, a middle Eocene archaeocete (Mammalia, Cetacea) from Western Kutch, India: Journal of Vertebrate Paleontology, v. 6, p. 326–349.10.1080/02724634.1986.10011629CrossRefGoogle Scholar
LaDuke, T.C., 1991, Morphometric variability of the precaudal vertebrae of Thamnophis sirtalis sirtalis (Serpentes: Colubridae), and implications for interpretation of the fossil record [Ph.D. dissertation]: New York, The City University of New York, 235 p.Google Scholar
LaDuke, T.C., Krause, D.W., Scanlon, J.D. and Kley, N.J., 2010, A Late Cretaceous (Maastrichtian) snake assemblage from the Maevarano Formation, Mahajanga Basin, Madagascar: Journal of Vertebrate Paleontology, v. 30, p. 109–138, https://doi.org/10.1080/02724630903409188CrossRefGoogle Scholar
Linnaeus, C., 1758, Systema Naturae per Regna Tria Naturae (tenth edition), Volume 1, Regnum Animale: Stockholm, Laurentii Salvii, 824 p.Google Scholar
Lucas, F.A., 1898, A new snake from the Eocene of Alabama: Proceedings of the United States National Museum, v. 21, p. 637, 638.10.5479/si.00963801.21-1164.637CrossRefGoogle Scholar
Lydekker, R., 1888, Notes on Tertiary Lacertilia and Ophidia: Geological Magazine, v. 5, p. 110–113.10.1017/S0016756800173480CrossRefGoogle Scholar
Marsh, O.C., 1892, Notice of new reptiles from the Laramie Formation: American Journal of Science, v. 43, p. 449–453.10.2475/ajs.s3-43.257.449CrossRefGoogle Scholar
McCartney, J.A., and Seiffert, E.R., 2016, A late Eocene snake fauna from the Fayum Depression, Egypt: Journal of Vertebrate Paleontology, v. 36, n. e1029580, https://doi.org/10.1080/02724634.2015.1029580CrossRefGoogle Scholar
McCartney, J.A., Roberts, E.M., Tapanila, L., and Oleary, M.A., 2018, Large palaeophiid and nigerophiid snakes from Paleogene Trans-Saharan Seaway deposits of Mali: Acta Palaeontologica Polonica, v. 63, p. 207–220, https://doi.org/10.4202/app.00442.2017CrossRefGoogle Scholar
Mohabey, D.M., Head, J.J., and Wilson Mantilla, J.A., 2011, A new species of the snake Madtsoia from the Upper Cretaceous of India and its paleobiogeographic implications: Journal of Vertebrate Paleontology, v. 31, p. 588–595, https://doi.org/10.1080/02724634.2011.560220CrossRefGoogle Scholar
Mosauer, W., 1932, On the locomotion of snakes: Science, v. 76, p. 583–585.10.1126/science.76.1982.583CrossRefGoogle ScholarPubMed
Müller, J., and Henle, F.G.J., 1837, Gattungen der Haifische und Rochen nach einer von ihm mit Herrn Henle unternommenen gemeinschaftlichen Arbeit über die Naturgeschichte der Knorpelfische: Berichte der Königlichen Preußischen Akademie der Wissenschaften zu Berlin, v. 2, p. 111–118.Google Scholar
Mukherjee, D., and Ray, S., 2012, Taphonomy of an upper Triassic vertebrate bonebed: a new rhynchosaur (Reptilia; Archosauromorpha) accumulation from India: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 333, p. 75–91, https://doi.org/10.1016/j.palaeo.2012.03.010CrossRefGoogle Scholar
Mukhopadhyay, S., and Shome, S., 1996, Depositional environment and basin development during early Palaeogene lignite deposition, western Kutch, Gujarat: Journal of the Geological Society of India, v. 47, p. 579–592.10.17491/jgsi/1996/470507CrossRefGoogle Scholar
Natarajan, A., Dasgupta, S., Rakshit, N., and Kashyap, Y., 2024, Taxonomic revision of the giant marine snake genus Pterosphenus Lucas, 1898, based on new fossil material from the middle Eocene (Bartonian) Harudi Formation of Kachchh (Kutch) Basin, India: Journal of Vertebrate Paleontology, v. 43, n. e2375332, https://doi.org/10.1080/02724634.2024.2375332CrossRefGoogle Scholar
Oppel, M., 1811, Die Ordnungen, Familien und Gattungen der Reptilien als Prodrom einer Naturgeschichte derselben: Munich, Joseph Lindauer, 87 p.10.5962/bhl.title.4911CrossRefGoogle Scholar
Owen, R., 1841, Description of some ophidiolites (Palæophis toliapicus) from the London Clay of Sheppey, indicating an extinct species of serpent: Transactions of the Geological Society ser. 2, v. 6, p. 209–210.10.1144/transgslb.6.1.209CrossRefGoogle Scholar
Owen, R., 1850, Ophidia (Palæophis, &c.), in Owen, R., ed., Monograph on the Fossil Reptilia of the London Clay and of the Bracklesham and Other Tertiary Beds: London, Palæontographical Society of London, p. 51–63.Google Scholar
Parmley, D., and Case, G.R., 1988, Palaeopheid snakes from the Gulf coastal region of North America: Journal of Vertebrate Paleontology, v. 8, p. 334–339.10.1080/02724634.1988.10011717CrossRefGoogle Scholar
Parmley, D., and DeVore, M., 2005, Palaeophid snakes from the late Eocene Hardie Mine local fauna of central Georgia: Southeastern Naturalist, v. 4, p. 703–722, https://doi.org/10.1656/1528-7092(2005)004[0703:PSFTLE]2.0.CO;2CrossRefGoogle Scholar
Parmley, D., and Reed, H.W., 2003, Size and age class estimates of North American Eocene palaeopheid snakes: Georgia Journal of Science, v. 61, p. 220–232.Google Scholar
Prasad, G.V.R., and Khajuria, C.K, 1996, Palaeoenvironment of the Late Cretaceous mammal-bearing intertrappean beds of Naskal, Andhra Pradesh, India: Memoirs of the Geological Society of India, v. 37, p. 337–362.Google Scholar
Prasad, G.V.R., and Rage, J.-C., 1995, Amphibians and squamates from the Maastrichtian of Naskal (India): Cretaceous Research, v. 16, p. 95–107.10.1006/cres.1995.1006CrossRefGoogle Scholar
Prasad, G.V.R., and Sahni, A., 1987, Coastal-plain microvertebrate assemblage from the terminal Cretaceous of Asifabad, peninsular India: Journal of the Palaeontological Society of India, v. 32, p. 5–19.10.1177/0971102319870102CrossRefGoogle Scholar
Pritchard, A.C., McCartney, J.A., Krause, D.W., and Kley, N.J., 2014, New snakes from the Upper Cretaceous (Maastrichtian) Maevarano Formation, Mahajanga Basin, Madagascar: Journal of Vertebrate Paleontology, v. 34, p. 1080–1093, https://doi.org/10.1080/02724634.2014.841706CrossRefGoogle Scholar
Pyron, R.A., Reynolds, R.G., and Burbrink, F.T., 2014, A taxonomic revision of boas (Serpentes: Boidae): Zootaxa, v. 3846, p. 249–260, https://doi.org/10.11646/zootaxa.3846.2.5CrossRefGoogle ScholarPubMed
Rage, J.-C., 1975, Un serpent du Paléocène du Niger: étude préliminaire sur l’origine des Caenophidiens (Reptilia, Serpentes): Comptes Rendus de l’Académie des Sciences de Paris, v. 281, p. 515–518.Google Scholar
Rage, J.-C., 1983a, Palaeophis colossaeus nov. sp. (le plus grand serpent connu?) de l’Éocène du Mali et le problème du genre chez les Palaeopheinae: Comptes Rendus des Séances de l’Académie des Sciences de Paris, v. 296, p. 1029–1032.Google Scholar
Rage, J.-C., 1983b, Les serpents aquatiques de l’Éocène Européen: définition des espèceset aspects stratigraphiques: Bulletin du Muséum National d’Histoire Naturelle, sér. 4, section C, Sciences de la Terre, Paléontologie, Géologie, Minéralogie, v. 5, p. 213–241.Google Scholar
Rage, J.-C., 1984, Handbuch der Paläoherpetologie, Teil 11, Serpentes: Stuttgart, Gustav Fischer Verlag, 80 p.Google Scholar
Rage, J.-C., and Prasad, G.V.R., 1992, New snakes from the Late Cretaceous (Maastrichtian) of Naskal, India: Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, v. 187, p. 83–97.10.1127/njgpa/187/1992/83CrossRefGoogle Scholar
Rage, J.-C., and Wouters, G., 1979, Découverte du plus ancien palaeopheidé (Reptilia, Serpentes) dans le Maestrichtien du Maroc: Geobios, v. 12, p. 293–296.10.1016/S0016-6995(79)80084-4CrossRefGoogle Scholar
Rage, J.-C., Bajpai, S., Thewissen, J.G., and Tiwari, B.N., 2003, Early Eocene snakes from Kutch, western India, with a review of the Palaeophiidae: Geodiversitas, v. 25, p. 695–716.Google Scholar
Rage, J.-C., Prasad, G.V.R., and Bajpai, S., 2004, Additional snakes from the uppermost Cretaceous (Maastrichtian) of India: Cretaceous Research, v. 25, p. 425–434, https://doi.org/10.1016/j.cretres.2004.02.003CrossRefGoogle Scholar
Rage, J.-C., Folie, A., Rana, R.S., Singh, H., Rose, K.D., and Smith, T., 2008, A diverse snake fauna from the early Eocene of Vastan Lignite Mine, Gujarat, India: Acta Palaeontologica Polonica, v. 53, p. 391–403, https://doi.org/10.4202/app.2008.0303Google Scholar
Rage, J.C., Vullo, R., and Neraudeau, D., 2016, The mid-Cretaceous snake Simoliophis rochebrunei Sauvage, 1880 (Squamata: Ophidia) from its type area (Charentes, southwestern France): redescription, distribution, and palaeoecology: Cretaceous Research, v. 58, p. 234–253, https://doi.org/10.1016/j.cretres.2015.10.010CrossRefGoogle Scholar
Rage, J.-C., Prasad, G.V.R., Verma, O., Khosla, A., and Parmar, V., 2020, Anuran Lissamphibian and squamate reptiles from the Upper Cretaceous (Maastrichtian) Deccan Intertrappean Sites in Central India, with a review of Lissamphibian and squamate diversity in the northward drifting Indian plate, in Prasad, G.V.R., and Patnaik, R., eds., Biological Consequences of Plate Tectonics: New Perspectives on Ppost-Gondwana Break-up: Cham, Switzerland, Springer Nature Switzerland, p. 99–121.10.1007/978-3-030-49753-8_6CrossRefGoogle Scholar
Ravikant, V., and Bajpai, S., 2010, Strontium isotope evidence for the age of Eocene fossil whales of Kutch, western India: Geological Magazine, v. 147, p. 473–477, https://doi.org/10.1017/S0016756810000099CrossRefGoogle Scholar
Rio, J.P., and Mannion, P.D., 2017, The osteology of the giant snake Gigantophis garstini from the upper Eocene of North Africa and its bearing on the phylogenetic relationships and biogeography of Madtsoiidae: Journal of Vertebrate Paleontology, v. 37, n. e1347179, https://doi.org/10.1080/02724634.2017.1347179CrossRefGoogle Scholar
Sahni, A., and Mishra, V.P., 1975. Lower Tertiary vertebrates from western India: Monograph of the Palaeontological Society of India, v. 3, p. 1–48.Google Scholar
Sauvage, H.E., 1880, Sur l’existence d’un reptile du type ophidien dans les couches à Ostrea columba des Charentes: Comptes Rendus Hebdomadaires des Séances de l’Académie des Sciences, v. 91, p. 671, 672.Google Scholar
Scanferla, C.A., and Canale, J.I., 2007, The youngest record of the Cretaceous snake genus Dinilysia (Squamata, Serpentes): South American Journal of Herpetology, v. 2, p. 76–81, https://doi.org/10.2994/1808-9798(2007)2[76:TYROTC]2.0.CO;2CrossRefGoogle Scholar
Serra-Kiel, J., Hottinger, L., Caus, E., Drobne, K., Ferrandez, C., et al., 1998, Larger foraminiferal biostratigraphy of the Tethyan Paleocene and Eocene: Bulletin de la Société Géologique de France, v. 169, p. 281–299.Google Scholar
Smith, K.T., and Georgalis, G.L., 2022, The diversity and distribution of Palaeogene snakes: a review with comments on vertebral sufficiency, in Gower, D., and Zaher, H., eds., The Origin and Early Evolution of Snakes: Cambridge, UK, Cambridge University Press, p. 55–84.10.1017/9781108938891.006CrossRefGoogle Scholar
Smith, T., Kumar, K., Rana, R.S., Folie, A., Solé, F., Noiret, C., Steeman, T., Sahni, A. and Rose, K.D., 2016, New early Eocene vertebrate assemblage from western India reveals a mixed fauna of European and Gondwana affinities: Geoscience Frontiers, v. 7, p. 969–1001, https://doi.org/10.1016/j.gsf.2016.05.001CrossRefGoogle Scholar
Smith-Woodward, A., 1901, On some extinct reptiles from Patagonia of the genera Miolania, Dinilysia, and Genyodectes: Proceedings of the Zoological Society of London, v. 70, p. 169–184.10.1111/j.1469-7998.1901.tb08537.xCrossRefGoogle Scholar
Snetkov, P.B., 2011, Vertebrae of the sea snake Palaeophis nessovi Averianov (Acrochordoidea, Palaeophiidae) from the Eocene of western Kazakhstan and phylogenetic analysis of the superfamily Acrochordoidea: Paleontological Journal, v. 45, p. 305–313, https://doi.org/10.1134/S0031030111030129CrossRefGoogle Scholar
Szyndlar, Z., and Georgalis, G.L., 2023, An illustrated atlas of the vertebral morphology of extant non-caenophidian snakes, with special emphasis on the cloacal and caudal portions of the column: Vertebrate Zoology, v. 73, p. 717–886, https://doi.org/10.3897/vz.73.e101372CrossRefGoogle Scholar
Tatarinov, L.P., 1963, First occurrence of ancient sea snakes in the USSR: Paleontologičeskij Žurnal, v. 2, p. 109–115.Google Scholar
Thewissen, J.G. and Bajpai, S., 2009, New skeletal material of Andrewsiphius and Kutchicetus, two Eocene cetaceans from India: Journal of Paleontology, v. 83, p. 635–663, https://doi.org/10.1666/08-045.1CrossRefGoogle Scholar
Thewissen, J.G.M., Cooper, L.N., George, J.C., and Bajpai, S., 2009, From land to water: the origin of whales, dolphins, and porpoises: Evolution: Education and Outreach, v. 2, p. 272–288, https://doi.org/10.1007/s12052-009-0135-2CrossRefGoogle Scholar
Wazir, W.A., Sehgal, R.K., Čerňanský, A., Patnaik, R., Kumar, N., Singh, A.P., Uniyal, P., and Singh, N.P., 2021, A find from the Ladakh Himalaya reveals a survival of madtsoiid snakes (Serpentes, Madtsoiidae) in India through the late Oligocene: Journal of Vertebrate Paleontology, v. 41, n. e2058401, https://doi.org/10.1080/02724634.2021.2058401CrossRefGoogle Scholar
Westgate, J.W., 2001, Paleoecology and biostratigraphy of marginal marine Gulf Coast Eocene vertebrate localities, in Gunnel, G.F., ed., Eocene Biodiversity: Unusual Occurrences and Rarely Sampled Habitats: New York, Kluwer Academic/Plenum, p. 263–297.10.1007/978-1-4615-1271-4_11CrossRefGoogle Scholar
Westgate, J.W., and Gee, C.T., 1990, Paleoecology of a middle Eocene mangrove biota (vertebrates, plants, and invertebrates) from southwest Texas: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 78, p. 163–177.10.1016/0031-0182(90)90210-XCrossRefGoogle Scholar
Westgate, J.W., and Ward, J.F., 1981, The giant aquatic snake Pterosphenus schucherti (Palaeophidae) in Arkansas and Mississipi: Journal of Vertebrate Paleontology, v. 1, p. 161–164.10.1080/02724634.1981.10011887CrossRefGoogle Scholar
Wilson Mantilla, J.A., Mohabey, D.M., Peters, S.E., and Head, J.J., 2010, Predation upon hatchling dinosaurs by a new snake from the Late Cretaceous of India: PLoS Biology, v. 8, n. e1000322, https://doi.org/10.1371/journal.pbio.1000322CrossRefGoogle Scholar
Zaher, H., Folie, A., Quadros, A.B., Rana, R.S., Kumar, K., Rose, K.D., Fahmy, M., and Smith, T., 2021, Additional vertebral material of Thaumastophis (Serpentes: Caenophidia) from the early Eocene of India provides new insights on the early diversification of colubroidean snakes: Geobios, v. 66, p. 35–43, https://doi.org/10.1016/j.geobios.2020.06.009CrossRefGoogle Scholar
Zaher, H., Mohabey, D.M., Grazziotin, F.G., and Wilson Mantilla, J.A., 2023, The skull of Sanajeh indicus, a Cretaceous snake with an upper temporal bar, and the origin of ophidian wide-gaped feeding: Zoological Journal of the Linnean Society, v. 197, p. 656–697, https://doi.org/10.1093/zoolinnean/zlac001CrossRefGoogle Scholar
Zigno, A. de, 1881, Nuove aggiunte alla fauna eocena del Veneto: Memorie del Reale Istituto Veneto di Scienze, Lettere ed Arti, v. 21, p. 775–790.Google Scholar
Zouhri, S., Khalloufi, B., Bourdon, E., de Broin, F.D.L., Rage, J.-C., M’haïdrat, L., Gingerich, P.D., and Elboudali, N., 2018, Marine vertebrate fauna from the late Eocene Samlat Formation of Ad-Dakhla, southwestern Morocco: Geological Magazine, v. 155, p. 1596–1620, https://doi.org/10.1017/S0016756817000759CrossRefGoogle Scholar
Zouhri, S., Gingerich, P.D., Khalloufi, B., Bourdon, E., Adnet, S., et al., 2021, Middle Eocene vertebrate fauna from the Aridal Formation, Sabkha of Gueran, southwestern Morocco: Geodiversitas, v. 43, p. 121–150, https://doi.org/10.5252/geodiversitas2021v43a5Google Scholar
Zvonok, E.A., and Snetkov, P.B., 2012, New findings of snakes of the genus Palaeophis Owen, 1841 (Acrochordoidea: Palaeophiidae) from the middle Eocene of Crimea: Proceedings of the Zoological Institute RAS, v. 316, p. 392–400, https://doi.org/10.31610/trudyzin/2012.316.4.392CrossRefGoogle Scholar