The imagery on this page is the basis for a paper entitled The Skull of the Rare Malaysian Snake Anomochilus leonardi Smith, based on High-Resolution X-ray Computed Tomography, by O. Rieppel and J.A. Maisano (2007, Zoological Journal of the Linnean Society 149:671-685). The abstract is as follows:

       The skull of the rare Malaysian snake Anomochilus leonardi is described in detail on the basis of a        high-resolution X-ray computed tomographic scan of a mature specimen. Its skull anatomy is compared        with that of Anomochilus weberi, as well as with that of scolecophidians and basal alethinophidians        such as Anilius, Cylindrophis, uropeltines and selected Booidea. Anomochilus leonardi is found to be        more paedomorphic than Anomochilus weberi. The genus Anomochilus most closely resembles        uropeltines in skull anatomy. Both Anomochilus and uropeltines develop a ‘central rod design’ of skull        morphology, which requires the presence of medial frontal pillars, in adaptation to burrowing habits.        These pillars are an alethinophidian characteristic, absent in the skull of scolecophidians, which        develop an ‘outer shell design’ in adaptation to burrowing. These results are discussed in the light of        the hypothesis that scolecophidians and basal (i.e. non-macrostomatan) alethinophidians are        ‘regressed macrostomatans’.

This specimen was found on the balcony of a two-story house within the campus of the Forest Research Institute Malaysia, Kepong, Selangor State. It is suspected that the specimen was accidentally dropped by a bird. It was made available to The University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Norsham Suhaina Yaakob of the Forest Research Institute Malaysia, Dr. Jessie Maisano of The University of Texas at Austin, and Mr. Alan Resetar of the Field Museum. Funding for scanning and image processing was provided by a National Science Foundation Assembling the Tree of Life grant (EF-0334961), The Deep Scaly Project: Resolving Squamate Phylogeny using Genomic and Morphological Approaches, to Drs. Jacques Gauthier of Yale University, Maureen Kearney of the Field Museum, Jessie Maisano of The University of Texas at Austin, Tod Reeder of San Diego State University, Olivier Rieppel of the Field Museum, Jack Sites of Brigham Young University, and John Wiens of SUNY Stonybrook.

The specimen was scanned by Matthew Colbert on 29 September 2004 along the coronal axis for a total of 553 slices. Each 1024x1024 pixel slice is 0.014 mm thick, with an interslice spacing of 0.014 mm and a field of reconstruction of 5.5 mm.

Literature

Bellairs Ad'A. 1949. Observations on the snout of Varanus,and a comparison with that of other lizards and snakes. Journal of Anatomy 83: 116–146.

Boulenger AG. 1893. Catalogue of the Snakes in the British Museum (Natural History). Volume 1. London: Trustees of the British Museum.

Brongersma LD, Helle W. 1951. Notes on Indo-Australian snakes. 1. Proceedings Koninklijke Nederlandse Akademie van Wetenschappen 54C: 1–8.

Coates M, Ruta M. 2000. Nice snakes, shame about the legs. Trends in Ecology and Evolution 15: 503–507.

Cundall D, Rossman DA. 1993. Cephalic anatomy of the rare Indonesian snake genus Anomochilus. Zoological Journal of the Linnean Society 109: 235–273.

Cundall D, Wallach V, Rossman DA. 1993. The systematic relationships of the snake genus Anomochilus. Zoological Journal of the Linnean Society 109: 275–299.

Estes R, Frazzetta TH, Williams EE. 1970. Studies on the fossil snake Dinilysia patagonica Woodward. Part I. Cranial morphology. Bulletin of the Museum of Comparative Zoology 140: 25–74.

Frazzetta TH. 1959. Studies on the morphology and function of the skull in the Boidae (Serpentes). Part 1. Cranial differences between Python sebae and Epicrates cenchris. Bulletin of the Museum of Comparative Zoology 119: 453–472.

Frazzetta TH. 1966. Studies on the morphology and function of the skull in the Boidae (Serpentes). Part 2. Morphology and function of the jaw apparatus in Python sebae and Python molurus. Journal of Morphology 118: 217–296.

Gower DJ, Vidal N, Spinks JN, McCarthy CJ. 2005. The phylogenetic position of Anomochilidae (Reptilia: Serpentes): first evidence from DNA sequences. Journal of Zoological Systematics and Evolutionary Research 43: 315–320.

Groombridge BC. 1979a. Variations in morphology of the superficial palate of henophidian snakes and some possible systematic implications. Journal of Natural History 13: 661–680.

Groombridge BC. 1979b. On the vomer in Acrochordidae (Reptilia: Serpentes), and its cladistic significance. Journal of Zoology, London 189: 559–567.

Haas G. 1930. Über das Kopfskelett und die Kaumuskulatur der Typhlopiden und Glauconiiden. Zoologisches Jahrbuch, Abteilung für Anatomie und Ontogenie der Tiere 52: 1–94.

Kley NJ. 2006. Morphology of the lower jaw and suspensorium in the Texas blindsnake, Leptotyphlops dulcis (Scolecophidia: Leptotyphlopidae). Journal of Morphology 267: 494–515.

Kluge AG. 1993. Aspidites and the phylogeny of pythonine snakes. Records of the Australian Museum Supplement 19: 1–77.

Lee MSY. 2005. Squamate phylogeny, taxon sampling, and data congruence. Organisms, Diversity and Evolution 5: 25– 45.

Lee MSY, Caldwell MW. 1998. Anatomy and relationships of Pachyrhachis problematicus, a primitive snake with hind limbs. Philosophical Transactions of the Royal Society of London B 352: 1521–1552.

Lidth de Jeude TW. 1890. Reptilia from the Malay Archipelago. II. Ophidia. In: Weber M, ed. Zoologische Ergebnisse einer Reise in Niederländisch Ost-Indien, Vol. 1. Leiden: E.J. Brill, 178–253.

Lidth de Jeude TW. 1922. Snakes from Sumatra. Zoologische Mededeelingen 6: 239–253.

Lim BL, Mohd. Sharef bin Kamarudin. 1975. Notes on new locality records of some rare snakes in peninsular Malaysia. Malayan Nature Journal 29: 23–27.

McDowell SB. 1975. A catalogue of the snakes of New Guinea and the Solomons, with special reference to those of the Bernice P. Bishop Museum. II. Anilioidea and Pythoninae. Journal of Herpetology 9: 1–80.

McDowell SB. 1987. Systematics. In: Seigel RA, Collins JT, Novak SS, eds. Snakes: ecology and evolutionary biology. New York: Macmillan, 3–50.

Oelrich TM. 1956. The anatomy of the head of Ctenosaura pectinata (Iguanidae). Miscellaneous Publications, Museum of Zoology, University of Michigan 94: 1–122.

Polcyn MJ, Jacobs LL, Haber A. 2005. A morphological model and CT assessment of the skull of Pachyrhachis problematicus (Squamata, Serpentes), a 98 million year old snake with legs from the Middle East. Palaeontologia Electronica 8.1.26A.

Rage J-C, 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: 513–520.

Rage J-C, Escuillié F. 2003. The Cenomanian: stage of hindlimbed snakes. Carnets de Géologie 2003/01: 1–11.

Rieppel O. 1977. Studies on the skull of the Henophidia (Reptilia, Serpentes). Journal of Zoology, London 181: 145–173.

Rieppel O. 1978. The evolution of the naso-frontal joint in snakes and its bearing on snake origins. Zeitschrift für Zoologische Systematik und Evolutionsforschung 16: 14–27.

Rieppel O. 1979a. The evolution of the basicranium in the Henophidia (Reptilia, Serpentes). Zoological Journal of the Linnean Society 66: 411–431.

Rieppel O. 1979b. The braincase of Typhlops and Leptotyphlops (Reptilia, Serpentes). Zoological Journal of the Linnean Society 65: 161–176.

Rieppel O. 1980. The sound transmitting apparatus of primitive snakes and its phylogenetic significance. Zoomorphology 96: 45–62.

Rieppel O. 1988. A review of the origin of snakes. Evolutionary Biology 22: 37–130.

Rieppel O, Kearney M. 2001. The origin of snakes: limits of a scientific debate. Biologist 48: 110–114.

Rieppel O, Zaher H. 2000. The intramandibular joint in squamates, and the phylogenetic relationships of the fossil snake Pachyrhachis problematicus Haas. Fieldiana (Geology) N.S. 43: 1–69.

Rieppel O, Zaher H. 2002. The skull of the Uropeltinae (Reptilia, Serpentes), with special reference to the otico-occipital region. Bulletin of the Natural History Museum, Zoological Series 68: 123–130.

Rieppel O, Zaher H, Tchernov E, Polcyn MJ. 2003. The anatomy and relationships of Haasiophis terrasanctus, a fossil snake with well-developed hind limbs from the mid-Cretaceous of the Middle East. Journal of Paleontology 77: 336–358.

Scanlon JD. 2005. Cranial morphology of the Plio-Pleistocene giant madtsoiid snake Wonambi naracoortensis. Acta Palaeontologica Polonica 50: 139–180.

Scanlon JD, Lee MSY. 2000. The Pleistocene serpent Wonambi and the early evolution of snakes. Nature 403: 416–420.

Smith MA. 1940. A new snake of the genus Anomochilus from the Malay Peninsula. Annals and Magazine of Natural History 11: 447–449.

Stuebing RB, Goh R. 1993. A new record of Leonard's pipe snake, Anomochilus leonardi Smith (Serpentes: Uropeltidae: Cylindrophinae) from Sabah, northwestern Borneo. Raffles Bulletin of Zoology 42: 311–314.

Tchernov EO, Rieppel O, Zaher H, Polcyn MJ, Jacobs LL. 2000. A fossil snake with limbs. Science 287: 2010–2012.

Underwood G. 1967. A contribution to the classification of snakes. London: British Museum (Natural History).

Vidal N, David P. 2004. New insights into the early history of snakes inferred from two nuclear genes. Molecular Phylogenetics and Evolution 31: 783–787.

Vidal N, Hedges SB. 2004. Molecular evidence for a terrestrial origin of snakes. Proceedings of the Royal Society of London B Suppl. 271: 226–229.

Williams EE. 1959. The occipito-vertebral joint in the burrowing snakes of the family Uropeltidae. Breviora 106: 1–10.

Yaakob NS. 2003. A record of Anomochilus leonardi Smith, 1940 (Anomochilidae) from Peninsular Malaysia. Hamadryad 27: 285–286.

Zaher H. 1998. The phylogenetic position of Pachyrhachis within snakes (Squamata, Lepidosauria). Journal of Vertebrate Paleontology 18: 1–3.

Three-dimensional volumetric renderings of the skull with the jaw removed, and of the isolated left mandible. All are less than 2mb except skull roll movie, which is 3mb.

Skull yaw movie	Skull pitch movie	Skull roll movie
Mandible yaw movie	Mandible pitch movie	Mandible roll movie