Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-25T18:59:06.655Z Has data issue: false hasContentIssue false

The anatomy and relationships of Haasiophis terrasanctus, a fossil snake by well-developed hind limbs from the Mid-Cretaceous of the Middle East

Published online by Cambridge University Press:  20 May 2016

Olivier Rieppel
Affiliation:
Department of Geology, The Field Museum, 1400 S. Lake Shore Drive, Chicago, Illinois 60605-2496,
Hussam Zaher
Affiliation:
Universidade de Sao Paulo, Instituto de Biociencias, Departamento de Zoologia, Rua do Matao, Travessa 14, Cidade Universitaria, 05508-900 Sao Paulo, SP, Brazil,
Eitan Tchernov
Affiliation:
Dept. of Evolution, Systematics and Ecology, Hebrew University, Berman-Lubin Buildings, Givat Ram, Jerusalem 91904, Israel,
Michael J. Polcyn
Affiliation:
Shuler Museum of Paleontology, Southern Methodist University, Dallas, Texas 75275,

Abstract

The fossil snake species Haasiophis terrasanctus Tchernov, Rieppel, Zaher, Polcyn, and Jacobs, 2000, from the early Upper Cretaceous of the Middle East, is described and illustrated, following a review of the current debate on snake relationships and origins. The description and discussion presented here adds important detail to the knowledge of this taxon and its phylogenetic significance beyond the limited account presented in the original description of Haasiophis. The species is remarkable in that it shows the skull of a relatively advanced (i.e., macrostomatan) snake, yet preserves well-developed hind limbs. The hind limb includes a femur, tibia, fibula, astragalus, calcaneum, distal tarsal four, and remains of four metatarsals and two phalanges. Haasiophis cannot be considered a juvenile specimen of Pachyrhachis. The implications of the presence of well-developed hind limbs in Haasiophis, Pachyrhachis, and Podophis for the cladistic analysis of the phylogenetic interrelationships of these fossil snakes is discussed. The presence of well-developed hind limbs in Pachyrhachis and Haasiophis also creates methodological problems for the cladistic analysis of the phylogenetic relationships of these fossil snakes. Scenarios of snake origins are reviewed and found to be deficient in the absence of a well-corroborated hypothesis of snake relationships within Squamata.

Type
Research Article
Copyright
Copyright © The Paleontological Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Augé, M. L. 1992. Une espèce nouvelle d'Ophisaurus (Lacertilia, Anguidae) de l'Oligocène des phosphorites du Quercy. Révision de la sous-famille des Anguinae, Paläontologische Zeitschrift, 66:159175.CrossRefGoogle Scholar
Barrie, D. J. 1990. Skull elements and additional remains of the Pleistocene boid snake Wonambi naracoortensis . Memoirs of the Queensland Museum, 28:139151.Google Scholar
Baur, G. 1895. Cope on the temporal part of the skull, and on the systematic position of the Mosasauridae—a reply. American Naturalist, 29:9981002.Google Scholar
Baur, G. 1896. The paroccipital of the Squamata and the affinities of the Mosasauridae once more. A rejoinder to Professor E.D. Cope. American Naturalist, 30:143152.Google Scholar
Bell, G. L. Jr. 1997. A phylogenetic revision of North American and Adriatic mosasaurs, p. 293332. In Callaway, J. M. and Nicholl, E. L. (eds.), Ancient Marine Reptiles. Academic Press, San Diego.CrossRefGoogle Scholar
Bellairs, A.d'A., and Underwood, G. 1951. The origin of snakes. Biological Reviews, 26:193237.CrossRefGoogle ScholarPubMed
Boulenger, G. A. 1891. Notes on the osteology of Heloderma horridum and H. suspectum with remarks on the systematic position of the Helodermatidae and on the vertebrae of the Lacertilia. Proceedings of the zoological Soociety of London, 1891:109118.Google Scholar
Braun, M. 1970. Facies changes of the Judea group, in Judea and Samaria. Israel Geological Society, Annual Meeting, 1970:2935.Google Scholar
de Broin, F., and Werner, C. 1998. New Late Cretaceous turtles from the Western Desert, Egypt. Annals de Paléontologie, 84:131214.CrossRefGoogle Scholar
Caldwell, M. W. 1999. Squamate phylogeny and the relationships of snakes and mosasauroids. Zoological Journal of the Linnean Society, 125:115147.CrossRefGoogle Scholar
Caldwell, M. W. 2000a. On the phylogenetic relationships of Pachyrhachis within snakes: a response to Zaher (1998). Journal of Vertebrate Paleontology, 20:187190.CrossRefGoogle Scholar
Caldwell, M. W. 2000b. On the aquatic squamate Dolichosaurus longicollis Owen, 1850 (Cenomanian, Upper Cretaceous), and the evolution of elongate necks in squamates. Journal of Vertebrate Paleontology, 20:720735.CrossRefGoogle Scholar
Caldwell, M. W., and Lee, M. S. Y. 1997. A snake with legs from the marine Cretaceous of the Middle East. Nature, 386:705709.CrossRefGoogle Scholar
Calligaris, R. 1988. I rettili fossili degli “strati calcarei ittiolotici di Comeno” e dell' isola Lesina. Atti de Museo Civico di Storia Naturale di Trieste, 41:85125.Google Scholar
Camp, C. L. 1923. Classification of the lizards. Bulletin of the American Museum of Natural History, 48:289481.Google Scholar
Carroll, R. L. 1988. Vertebrate Paleontology and Evolution. W.H. Freeman & Co., New York, 698 p.Google Scholar
Carroll, R. L., and deBraga, M. 1992. Aigialosaurs: mid-Cretaceous varanoid lizards. Journal of Vertebrate Paleontology, 12:6668.CrossRefGoogle Scholar
Chalifa, Y. 1985. Saurorhamphus judeaensis (Salmoniformes: Enchodontidae), a new longirostrine fish from the Cretaceous (Cenomanian) of Ein-Yabrud, near Jerusalem. Journal of Vertebrate Paleontology, 5:181193.CrossRefGoogle Scholar
Chalifa, Y. 1989a. Two new species of longirostrine fishes from the early Cenomanian (Late Cretaceous) of Ein-Yabrud, Israel, with comments on the phylogeny of the Dercetidae. Journal of Vertebrate Paleontology, 9:314328.CrossRefGoogle Scholar
Chalifa, Y. 1989b. New species of Enchodus (Pisces: Enchodontoidei) from the lower Cenomanian of Ein-Yabrud, Israel. Journal of Paleontology, 63:356364.CrossRefGoogle Scholar
Chalifa, Y. 1989c. Yabrudichthys and Serrilepis, two new genera of enchodontids (Teleostei) from the lower Cenomanian beds of 'Ein Yabrud, Israel. Israel Journal of Zoology, 26:1138.Google Scholar
Chalifa, Y., and Tchernov, E. 1982. Pachyamia latimaxillaris, a new genus and species (Actinopterygii: Amiidae) from the Cenomanian of Jerusalem. Journal of Vertebrate Paleontology, 2:269285.CrossRefGoogle Scholar
Coates, M., and Ruta, M. 2000. Nice snakes, shame about the legs. TREE, 15:503507.Google ScholarPubMed
Cohn, M. J., and Tickle, C. 1999. Developmental basis of limblessness and axial patterning in snakes. Nature, 399:474479.CrossRefGoogle ScholarPubMed
Cope, E. D. 1869. On the reptilian order Pythonomorpha and Streptosauria. Proceedings of the Boston Society of Natural History, 12:250261.Google Scholar
Cope, E. D. 1872. On the geology and paleontology of the Cretaceous strata of Kansas, p. 318349. In Hayden, F. V. (ed.), Preliminary Report on the United States Geological Survey of Montana and Portions of Adjacent Territories; being a Fifth Annual Report of Progress, Pt. 3, Paleontology. Washington.Google Scholar
Cope, E. D. 1878. Professor Owen on the Pythonomorpha. Bulletin of the U.S. Geological and Geographical Survey, Territories (Hayden Survey), 4:299311.Google Scholar
Cope, E. D. 1895a. Baur on the temporal part of the skull, and on the morphology of the skull in the Mosasauridae. American Naturalist, 29:855859.Google Scholar
Cope, E. D. 1895b. Reply to Dr. Baur's critique of my paper on the paroccipital bone of the scaled reptiles and the systematic position of the Pythonomorpha. American Naturalist, 29:10031005.Google Scholar
Cope, E. D. 1896. Criticism of Dr. Baur's rejoinder on the homologies of the paroccipital bone etc. American Naturalist, 30:147152.Google Scholar
Cundall, D., and Greene, H. W. 2000. Feeding in snakes, p. 293333. In Schwenk, K. (ed.), Feeding, Form, Function, and Evolution in Tetrapod Vertebrates. Academic Press, San Diego.Google Scholar
Cundall, D., Wallach, V., and Rossmann, D. A. 1993. The systematic relationships of the snake genus Anomochilus . Zoological Journal of the Linnean Society, 109:273299.CrossRefGoogle Scholar
Estes, R., Frazzetta, T. H., and Williams, E. E. 1970. Studies on the fossil snake Dinilysia patagonica Woodward, Pt. I, cranial morphology. Bulletin of the Museum of Comparative Zoology, 140:2574.Google Scholar
Estes, R., deQuieroz, K., and Gauthier, J. 1988. Phylogenetic relationships within Squamata, p. 119281. In Estes, R. and Pregill, G. (eds.), Phylogenetic Relationships of the Lizard Families. Stanford University Press, Stanford.Google Scholar
Evans, S. E., and Barbadillo, L. J. 1998. An unusual lizard (Reptilia: Squamata) from the Early Cretaceous of Las Hoyas, Spain. Zoological Journal of the Linnean Society, 124:235265.CrossRefGoogle Scholar
Farris, J. S. 1983. The logical basis of phylogenetic analysis, p. 736. In Platnick, N. and Funck, V. (eds.), Advances in Cladistics. Columbia University Press, New York.Google Scholar
de Fejérvary, G. J. 1918. Contributions to a monography on the fossil Varanidae and Megalanidae. Annales historico-naturales Musei Nationalis Hungarici, 16:341467.Google Scholar
Forstner, M. R., Davis, S. K., and Arévalo, E. 1995. Support for the hypothesis of anguimorph ancestry for the suborder Serpentes from phylogenetic anaysis of mitochondrial DNA sequences. Molecular Phylogenetics and Evolution, 4:93102.CrossRefGoogle Scholar
Frazzetta, T. H. 1959. Studies on the morphology and function of the skull in the Boidae (Serpentes), Pt. 1, cranial differences between Python sebae and Epicrates cenchris . Bulletin of the Museum of Comparative Zoology, 119:453472.Google Scholar
Frazzetta, T. H. 1966. Studies on the morphology and function of the skull in the Boidae (Serpentes), Pt. 2, Morphology and function of the jaw apparatus in Python sebae and Python molurus . Journal of Morphology, 118:217296.CrossRefGoogle Scholar
Gayet, M. 1980a. Recherches sur l'Ichthyofaune Cenomanienne des Monts de Judée: “Acanthopterygiens”. Annales de Paléontologie (Vertébrés), 66:75128.Google Scholar
Gayet, M. 1980b. Recherches sur L'ichthyofaune cénomanienne des monts de Judée: les acanthopterygiens. Annales de Paléontologie (Vertébrès), 66:75128.Google Scholar
Gayet, M. 1980c. Contribution à l'étude anatomique et systématique des poissons cénomaniens du Liban, anciennement placés dans les acanthoptérigiens. Mémoires du Muséum national d'Histoire naturelle, Sér. C, 44:1150.Google Scholar
Gayet, M. 1980d. Découverte dans le Crétacé de Hadjula (Liban) du plus ancien Caproidae connu. Étude anatomique et phylogénétique. Bulletin du Muséum national d'Histoire naturelle, (4) 2:259269.Google Scholar
Gayet, M. 1985. Gonorhynchiforme nouveau du Cénomanien inferiéur marin de Ramallah (Mont de Judée): Judeichthys haasi nov. gen. nov. spec. (Teleostei; Ostariophysis, Judeichthydae, nov. fam.). Bulletin du Muséum national d'Histoire naturelle, (4) 7:6585.Google Scholar
Gorjanovic-Kramberger, K. 1901. Einige Bemerkungen zu Opetiosauurus buccichi Kornhuber. Verhandlungen der k.k. geologischen Reichsanstalt, Wien, 1901:271272.Google Scholar
Graham, A., and McGonnell, I. 1999. Developmental evolution: this side of paradise. Current Biology, 9:R630R632.CrossRefGoogle Scholar
Grande, L., and Bemis, W. E. 1998. A comprehensive phylogenetic study of amiid fishes (Amiidae) based on comparative skeletal anatomy. An empirical search for interconnected patterns of natural history. Society of Vertebrate Paleontology, Memoir 4, i–x, 690 p.CrossRefGoogle Scholar
Grandstein, F. M., Agterberg, F. P., Ogg, J. G., Hardenbol, J., Van Veen, P., Thierry, J., and Huang, Z. 1995. A Triassic, Jurassic and Cretaceous time scale, p. 95126. In Berggren, W. A., Kent, D. V., Aubry, M.-P., and Hardenbol, J. (eds.), Geochronology, Time Scales and Global Stratigraphic Correlation. Society for Sedimentary Geology, Special Publication, 54.Google Scholar
Greene, H. W. 1997. Snakes. University of California Press, Berkeley, xiii + 351 p.CrossRefGoogle Scholar
Greene, H. W., and Cundall, D. 2000. Limbless tetrapods and snakes with legs. Science, 287:19391941.CrossRefGoogle ScholarPubMed
Greer, A. E. 1991. Limb reduction in squamates: identification of the lineages and discussion of the trends. Journal of Herpetology, 25:166173.CrossRefGoogle Scholar
Greer, A. E. 1992. Hyperphalangy in squamates: insight on the reacquisition of primitive character states in limb-reduced lineages. Journal of Herpetology, 26:327329.CrossRefGoogle Scholar
Guibé, J. 1970. La réduction des members, p. 194201. In Grassé, P.-P. (ed.), Traîté de Zoologie, Volume 14, fasc 2: Reptiles, Charactères Généraux et Anatomie. Masson et Cie., Paris.Google Scholar
Haas, G. 1930a. Über das Kopfskelett und die Kaumuskulatur der Typhlopiden und Glauconiiden. Zoologische Jahrbücher, Abteilung für Anatomie und Ontogenie der Tiere, 52:194.Google Scholar
Haas, G. 1930b. Über die Kaumuskulatur und die Schädelmechanik einiger Wühlschlangen. Zoologische Jahrbücher, Abteilung für Anatomie und Ontogenie der Tiere, 52:194.Google Scholar
Haas, G. 1962. Remarques concernant les relations phylogéniques des diverses families d'ophidiens fondées sur la différenciation de la musculature mandibulaire. Colloques Internationaux du Centre National de la Recherche Scientifique, 104:215241.Google Scholar
Haas, G. 1964. Anatomical observations on the head of Liotyphlops albirostris (Typhlopidae, Ophidia). Acta Zoologica, Stockholm, 45:162.CrossRefGoogle Scholar
Haas, G. 1968. Anatomical observations on the head of Anomalepis aspinosus (Typhlopidae, Ophidia). Acta Zoologica, Stockholm, 49:63139.CrossRefGoogle Scholar
Haas, G. 1978a. A Cretaceous pleurodire turtle from the surroundings of Jerusalem. Israel Journal of Zoology, 27:2033.Google Scholar
Haas, G. 1978b. A new turtle of the genus Podocnemis from the lower Cenomanian of 'Ein Yabrud. Israel Journal of Zoology, 27:169175.Google Scholar
Haas, G. 1979. On a new snakelike reptile from the Lower Cenomanian of Ein Jabrud, near Jerusalem. Bulletin du Muséum National d'Histoire Naturelle, (4) 1:5164.Google Scholar
Haas, G. 1980a. Pachyrhachis problematicus Haas, snakelike reptile from the Lower Cenomanian: ventral view of the skull. Bulletin du Muséum National d'Histoire Naturelle, (4) 2:87104.Google Scholar
Haas, G. 1980b. Remarks on a new ophiomorph reptile from the lower Cenomanian of Ein Jabrud, Israel, p. 177192. In Jacobs, L. L. (ed.), Aspects of Vertebate History. Museum of Northern Arizona Press, Flagstaff.Google Scholar
Hallermann, J. 1998. The ethmoidal region of Dibamus taylori (Squamata: Dibamidae), with a phylogenetic hypothesis on dibamid relationships within Squamata. Zoological Journal of the Linnean Society, 122:385426.CrossRefGoogle Scholar
Heckel, J. J. 1849. Die fossilien Fische des Libanon, p. 201242. In Russegger, J. v. (ed.), Reisen im Europa, Asien und Afrika, Volume 2. E. Schweizerbart, Stuttgart.Google Scholar
Hofstetter, R., and Gasc, J.-P. 1969. Vertebrae and ribs of Modern reptiles, p. 201310. In Gans, C., Parsons, T. S., and Bellairs, A.d'A. (eds.), Biology of the Reptilia, Volume 1. Academic Press, London.Google Scholar
Janensch, W. 1906. Über Archaeophis proavus Mass., eine Schlange aus dem Eozän des Monte Bolca. Beiträge zur Palaeontologie Österreich-Ungarns, 19:133.Google Scholar
Kley, N. J. 2001. Prey transport mechanisms in blindsnakes and the evolution of unilateral feeding systems in snakes. American Zoologist, 41:13211337.Google Scholar
Kley, N. J., and Brainerd, E. L. 1999. Feeding by mandibular raking in a snake. Nature, 401:369370.CrossRefGoogle Scholar
Kluge, A. G. 1991. Boine snake phylogeny and research cycles. Miscellaneous Publications, Museum of Zoology, University of Michigan, 178:158.Google Scholar
Kluge, A. G. 1993a. Aspidites and the phylogeny of pythonine snakes. Records of the Australian Museum, Supplement 19:177.CrossRefGoogle Scholar
Kluge, A. G. 1993b. Calabaria and the phylogeny of erycine snakes. Zoological Journal of the Linnean Society, 107:293351.CrossRefGoogle Scholar
Kornhuber, A. 1873. Über einen neuen fossilen Saurier aus Lesina. Abhandlungen der K.K. geologischen Reichsanstalt, Wien, 17:124.Google Scholar
Kornhuber, A. 1901. Eine neue fossile Eidechse aus den unteren Kreideschiefern der Insel Lesina in Dalmatien. Abhandlungen der k.k. geologischen Reichsanstalt, Wien, 15:124.Google Scholar
Lee, M. S. Y. 1997a. The phylogeny of varanoid lizards and the affinities of snakes. Philosophical Transactions of the Royal Society of London, B 352:5391.CrossRefGoogle Scholar
Lee, M. S. Y. 1997b. On snake-like dentition in mosasaurian lizards. Journal of Natural History, 31:303314.CrossRefGoogle Scholar
Lee, M. S. Y. 1998. Convergent evolution and character correlation in burrowing reptiles: towards a resolution of squamate relationships. Biological Journal of the Linnean Society, 65:369453.CrossRefGoogle Scholar
Lee, M. S. Y. 2000. Soft anatomy, diffuse homoplasy, and the relationships of lizards and snakes. Zoologica Scripta, 29:101130.CrossRefGoogle Scholar
Lee, M. S. Y., Bell, G. L. Jr., and Caldwell, M. W. 1999. The origin of snake feeding. Nature, 400:655657.CrossRefGoogle Scholar
Lee, M. S. Y., and Caldwell, M. W. 1998. Anatomy and relationships of Pachyrhachis problematicus, a primitive snake with hind limbs. Philosophical Transactions of the Royal Society of London, B 352:15211552.CrossRefGoogle Scholar
Lee, M. S. Y., and Caldwell, M. W. 2000. Adriosaurus and the affinities of mosasaurs, dolichosaurs, and snakes. Journal of Paleontology, 74:915937.CrossRefGoogle Scholar
Lee, M. S. Y., Caldwell, M. W., and Scanlon, J. D. 1999. A second primitive marine snake: Pachyophis woodwardi from the Cretaceous of Bosnia-Herzogewina. Journal of Zoology, London, 248:509520.CrossRefGoogle Scholar
Lewy, Z., and Raab, M. 1976. Mid-Cretaceous stratigraphy of the Middle East. Muséum d'Histoire Naturelle de Nice, Annales, 4:121.Google Scholar
Linnaeus, C. 1758. Systerna naturae, 10th ed.Google Scholar
McDowell, S. B. 1975. A catalogue of the snakes of New Guinea and the Solomns, with special reference to those in the Bernice P. Bishop Museum, Pt. II, Anilioidea and Pythoninae. Journal of Herpetology, 9:180.CrossRefGoogle Scholar
McDowell, S. B., and Bogert, C. M. 1954. The systematic position of Lanthanotus and the affinities of anguinomorphan lizards. Bulletin of the American Museum of Natural History, 105:1142.Google Scholar
Moody, R. T. 1997. The paleogeography of marine and coastal turtles of the North Atlantic and Trans-Saharan regions, p. 259278. In Callaway, J. M. and Nicholls, E. L. (eds.), Ancient Marine Reptiles. Academic Press, San Diego.CrossRefGoogle Scholar
Müller, Joh. 1831. Beiträge zur Anatomie und Naturgeschichte der Amphibien. Zeitschrift für Physiologie, 4:190275.Google Scholar
Nicholls, E. L. 1997. Introducion, p. 219223. In Callaway, J. M. and Nicholls, E. L. (eds.), Ancient Marine Reptiles. Academic Press, San Diego.CrossRefGoogle Scholar
Nopcsa, F. 1903. Über die Varanus-Artigen Lacerten Istriens. Beiträge zur Palaeontologie und Geologie Österreich-Ungarns, 15:3142.Google Scholar
Nopcsa, F. 1908. Zur Kenntnis der fossilen Eidechsen. Beiträge zur Palaeontologie und Geologie Österreich-Ungarns, 21:3362.Google Scholar
Nopcsa, F. 1923. Eidolosaurus und Pachyophis. Zwei neue Neocom-Reptilien. Palaeontographica, 65:97154.Google Scholar
Nopcsa, F. 1925. Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens, II. Wirbeltier-Reste der Baharrîje-Stufe (unterstes Caenoman), 5, Die Symoliophis–Reste. Abhandlungen der Bayerischen Akademie der Wissenschaften, mathematisch-naturwissenschaftliche Abteilung, 30:127.Google Scholar
Osborn, H. F. 1899. A complete mosasaur skeleton, osseous and cartilaginous. Memoirs of the American Museum of Natural History, 1:167188.Google Scholar
Owen, R. 1877. On the rank and affinities in the reptilian class of Mosasauridae Gervais. Quarterly Journal of the Geological Society of London, 33:682715.CrossRefGoogle Scholar
Owen, R. 1878. On the affinities of the Mosasauridae Gervais, as exemplified in the bony structure of the fore fin. Quarterly Journal of the Geological Society of London, 34:784–753.CrossRefGoogle Scholar
Patterson, C. 1967. New cretaceous berycoid fishes from Lebanon. Bulletin of the British Museum of Natural History, Geology, 14:1109.Google Scholar
Polcyn, M. J., Tchernov, E., and Jacobs, L. L. 1999. The Cretaceous biogeography of the eastern Mediterranean with a description of a new basal mosasauroid from 'Ein Yabrud, Israel, p. 259290. In Tomida, Y., Rich, T. H., and Vickers-Rich, P. (eds.), Proceedings of the Second Gondwanan Dinosaur Symposium. National Science Museum Monographs 15, Tokyo.Google Scholar
Popper, K. R. 1979. Die beiden Grundprobleme der Erkenntnistheorie. J.C.B. Mohr, Tübingen.Google Scholar
Rage, J.-C. 1982. La phylogénie des Lépidosauriens (Reptilia): Une approche cladistique. Comptes Rendus, Académie des Sciences, Paris, 294:563566.Google Scholar
Rage, J.-C. 1984. Serpentes, p. 180. In Wellnhofer, P. (ed.), Handbuch der Paläoherpetologie, Teil 11. G. Fischer, Stuttgart.Google Scholar
Rage, J.-C., and Escuillié, F. 2000. Un nouveau serpent bipède du Cénomanien (Crétacé). Implications phylétiques. Comptes Rendus à l' Académie des Sciences, Paris, Sciences de la Terre et des Planètes, 330:513520.Google Scholar
Reeder, T. W. 1995. Phylogenetic placement of snakes within the Squamata: evidence from molecules and morphology, p. 166. In American Society of Ichthyologists and Herpetologists, Program, and Abstracts. University of Alberta, Canada.Google Scholar
Rieppel, O. 1976. The homology of the laterosphenoid bone in snakes. Herpetologica, 32:426429.Google Scholar
Rieppel, O. 1984. Miniaturization of the lizard skull: its functional and evolutionary implications, p. 503520. In Ferguson, M. W. J. (ed.), The Structure, Development and Evolution of Reptiles. Zoological Society of London Symposia, Volume 52. Academic Press, London.Google Scholar
Rieppel, O. 1988. A review of the origin of snakes. Evolutionary Biology, 22:37130.CrossRefGoogle Scholar
Rieppel, O. 1993. Middle Triassic reptiles from Monte San Giorgio: recent results and future potential of analysis. Paleontologia Lombarda, n.s. 2:131144.Google Scholar
Rieppel, O. 1994. The Lepidosauromorpha: an overview with special emphasis on the Squamata, p. 2337. In Fraser, N.-C. and Sues, H.-D. (eds.), In the Shadow of the Dinosaurs. Early Mesozoic Tetrapods. Cambridge University Press, Cambridge.Google Scholar
Rieppel, O., and Kearney, M. 2001. The origin of snakes: limits of a scientific debate. Biologist, 48:110114.Google ScholarPubMed
Rieppel, O., and Kearney, M. 2002. Similarity. Biological Journal of the Linnean Society, 75:5982.CrossRefGoogle Scholar
Rieppel, O., and Zaher, H. 2000a. The intramandibular joint in squamates, and the phylogenetic relationships of the fossil snake Pachyrhachis problematicus Haas. Fieldiana (Geology), n.s. 43:169.Google Scholar
Rieppel, O., and Zaher, H. 2000b. The braincases of mosasaurs and Varanus, and the relationships of snakes. Zoological Journal of the Linnean Society, 129:489514.CrossRefGoogle Scholar
Rieppel, O., and Zaher, H. 2001. Re-building the bridge between mosasaurs and snakes. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 221:111132.CrossRefGoogle Scholar
Rieppel, O., Kluge, A. G., and Zaher, H. 2002. Testing the phylogenetic relationships of the Pleistocene snake Wonambi naracoortensis Smith. Journal of Vertebrate Paleontology, 22:812829.CrossRefGoogle Scholar
Ritgen, F. A. 1828. Versuch einer natürlichen Einteilung der Amphibien. Nova Acta Leopoldina, 14:245284.Google Scholar
Sander, P. M. 1989. The pachypleurosaurids (Reptilia: Nothosauria) from the Middle Triassic of Monte San Giorgio, (Switzerland), with the description of a new species. Philosophical Transactions of the Royal Society of London, B 325:561670.Google Scholar
Scanlon, J. D., and Lee, M. S. Y. 2000. The Pleistocene serpent Wonambi and the early evolution of snakes. Nature, 403:416420.CrossRefGoogle ScholarPubMed
Scanlon, J. D., Lee, M. S. Y., Caldwell, M. D., and Shine, R. 1999. The paleoecology of the primitive snake Pachyrhachis . Historical Biology, 13:127152.CrossRefGoogle Scholar
Senn, D. G., and Northcutt, R. G. 1973. The forebrain and midbrain of some squamates and their bearing on the origin of snakes. Journal of Morphology, 140:135152.CrossRefGoogle ScholarPubMed
Shachnai, E. 1969. Geology Map, Ramallah. Geological Survey of Israel, Jerusalem.Google Scholar
Shubin, N. H., and Alberch, P. 1986. A morphogenetic approach to the origin and basic organization of the tetrapod limb. Evolutionary Biology, 20:319387.Google Scholar
Sober, E. 1988. Reconstructing the Past. Parsimony, Evolution, and Inference. The MIT Press, Cambridge, Massachusetts.Google Scholar
Tchernov, E., Rieppel, O., Zaher, H., Polcyn, M. J., and Jacobs, L. J. 2000. A new fossil snake with limbs. Science, 287:20102012.CrossRefGoogle ScholarPubMed
Tchernov, E. O., Polcyn, M. J., and Jacobs, L. J. 2001. Application of computed tomography to Pachyrhachis problematicus, a snake with legs from the Cretaceous of Israel. Journal of Vertebrate Paleontology, 21:107A.Google Scholar
Trueman, J. W. H. 1998. Reverse successive weighting. Systematic Biology, 47:733737.CrossRefGoogle ScholarPubMed
Underwood, G. 1967. A Contribution to the Classification of Snakes. British Museum, London, ix + 179 p.Google Scholar
Vaeth, R. H., Rossman, D. A., and Shoop, W. 1985. Observations on tooth surface morphology in snakes. Journal of Herpetology, 19:2026.CrossRefGoogle Scholar
Wallach, V. 1984. A new name for Ophiomorphus colberti Haas. Journal of Herpetology, 18:329.CrossRefGoogle Scholar
Walls, G. 1940. Ophthalmological implications for the early history of snakes. Copeia, 1940:18.CrossRefGoogle Scholar
Walls, G. 1942. The Vertebrate Eye and its Adaptive Radiation. The Cranbrook Institute of Science, Bloomfield MI, xiv + 785 p.Google Scholar
Wiens, J. J. 2001. Character analysis in morphological phylogenetics: problem and solutions. Systematic Biology, 50:689699.CrossRefGoogle ScholarPubMed
Wood, R. C. 1984. Evolution of the pelomedusid turtles. Studia Geologica Salamanticensia, Special Volume 1 (Studia Palaeocheloniologica I):269282.Google Scholar
Young, B. A., and Kardong, K. V. 1966. Dentitional surface features in snakes (Reptilia: Serpentes). Amphibia–Reptilia, 17:261276.Google Scholar
Zaher, H. 1998. The phylogenetic position of Pachyrhachis within snakes (Squamata, Lepidosauria). Journal of Vertebrate Paleontology, 18:13.CrossRefGoogle Scholar
Zaher, H., and Rieppel, O. 1999a. Tooth implantation and replacement in squamates, with special reference to mosasaur lizards and snakes. American Museum Novitates, 3271:119.Google Scholar
Zaher, H., and Rieppel, O. 1999b. The phylogenetic relationships of Pachyrhachis problematicus, and the evolution of limblessness in snakes (Lepidosauria, Squamata). Comptes rendus de l'Académie des sciences, série IIa, Earth and Planetary Sciences, 329:831837.Google Scholar
Zaher, H., and Rieppel, O. 2000. A brief history of snakes. Herpetological Review, 31:7376.Google Scholar
Zaher, H., and Rieppel, O. 2002. On the phylogenetic relationships of the Cretaceous snakes with legs, with special reference to Pachyrhachis problematicus (Squamata, Serpentes). Journal of Vertebrate Paleontology, 22:104109.CrossRefGoogle Scholar