Order Squamata
Suborder Serpentes (Ophidia)

Phylogeny of snakes

There is no general agreement on the phylogeny of snakes. Here are a couple of hypotheses that have been proposed recently:

Classical model of snake phylogeny based on various authors (after Vidal & Hedges 2002b)

Phylogenetic relationships of Caenophidia based on Cadle (1987, 1994), McDowell (1987), Underwood and Kochva (1993), Knight and Mindell (1994), Heise et al. (1995), Kraus and Brown (1998), Zaher (1999), Vidal et al. (2000) and Vidal (2002). Traits: S, supralabial secretory serous cells; D, differentiated maxillary dentition. Terminal taxa written in bold possess a front-fanged venom system. Caenophidia other than Acrochordidae and lacking a front-fanged venom system are traditionally classified as 'Colubridae'. Pseudoxenodontines and homalopsines are not shown (unknown phylogenetic relationships).

Model by Wilcox et al. (2002) stressing the position of the dwarf boas (Tropidophiidae and the new family Ungaliophiidae)

Maximum-likelihood tree recovered from analysis of 1545 bp of mitochondrial DNA sequence spanning the 12S and 16S genes.Taxa in bold traditionally were placed in Tropidophiidae. Tree shown with support values from Bayesian analysis (above the branches)and nonparametric bootstrapping (below the branches). Xenophidion was not included in this analysis because DNA samples were not available. After Wilcox et al. (2002).

Model after Heise et al. (1995)

Phylogenetic tree of snakes based on mitochondrial 12s and 16s rRNA sequence data (8 18 aligned sites). An iguanid lizard (Sceloporus undtdatus) was included, and the tree was rooted with a tuatara (Sphenodon pzmtatzu). The tree was constructed using neighbor-joining with the Jukes-Cantor distance (scale bar). Confidence probability values are given for each branch.

Model after Vidal & Hedges (2002)

Phylogenetic relationships of snakes based on C-mos, 12-16S rRNA and cytochrome b sequences (bootstrap ME consensus tree, 2000 replicates, values above 50% are shown). Terminal taxa written in bold are fossorial (non macrostomatan). The C-mos alone analysis gives an alternative topology where the two 'anilioid' lineages are not basal alethinophidian snakes, but basal henophidian snakes.

Model of Caenophidian relationships after Vidal & Hedges (2002b)

Phylogenetic relationships of Caenophidia based on C-mos, 12-16S rRNA and ND4 sequences (bootstrap ME consensus tree, 2000 replicates, values above 50% are shown). Traits: S, supralabial secretory serous cells; D, differentiated maxillary dentition. Terminal taxa written in bold possess a front-fanged venom system.

References:

Cadle, J.E. 1987
Geographic distribution: problems in phylogeny and zoogeography, in: R.A. Seigel, J.T. Collins, S.S. Novak (Eds.), Snakes: ecology and evolutionary biology.
Macmillan Publ., New York, pp. 77&endash;105.

Cadle, J.E. (1994)
The colubrid radiation in Africa (Serpentes: Colubridae): phylogenetic relationships and evolutionary patterns based on immunological data.
Zool. J. Linn. Soc. 110 103&endash;140.

Heise, P. J.;Maxson, L. R.;Dowling, H. G.;Hedges, S. B. (1995)
Higher-level snake phylogeny inferred from mitochondrial DNA sequences of 12S rRNA and 16S rRNA genes
Mol Biol Evol 12 (2): 259-65

Highton, R.; Hedges, S.B.; Hass, C.A. & Dowling, H.G. (2002)
Snake relationships revealed by slowly-evolving proteins: further analysis and a reply.
Herpetologica 58 (2): 270-275

Knight, A.; D.P. Mindell (1994)
On the phylogenetic relationships of Colubrinae, Elapidae and Viperidae and the evolution of front fanged venom systems in snakes.
Copeia 1994: 1&endash;9.

McDowell, S.B. (1987)
Systematics. In: R.A. Siegel, J.T. Collins, and S.S. Novak (eds.), Snakes: ecology and evolutionary biology.
MacMillan Publ. Co, New York, pp. 3-50

Kraus, F. & W.M. Brown (1998)
Phylogenetic relationships of colubroid snakes based on mitochondrial DNA sequences.
Zool. J. Linn. Soc. 122: 455&endash;487.

Pough, F.H. (Editor), Robin M. Andrews, John E. Cadle, Mart Crump (1998)
Herpetology
Prentice-Hall, 544 pp.

Stimson,A.F. (1969)
Liste der rezenten Amphibien und Reptilien: Boidae
Das Tierreich Lfg. 89, XI + 49 pp
Walter de Gruyter, Berlin

Welch,K.R.G. (1994)
Snakes of the World - A Checklist. 2. Boas, Pythons, Shield-tails and Worm Snakes.
R & A Research and Information Ltd and KCM Books.

Wallach, V. & R. Günther, 1998
Visceral anatomy of the Malaysian snake genus Xenophidion, including a cladistic analysis and allocation to a new family.
Amphibia Reptilia, 19 (4): 385-404

Wilcox, T.P.; Derrick J. Zwickl; Tracy A. Heath and David M. Hillis (2002)
Phylogenetic relationships of the dwarf boas and a comparison of Bayesian and bootstrap measures of phylogenetic support.
Molecular Phylogenetics and Evolution 25 (2): 361-371

Vidal, N.; S.G. Kindl, A. Wong, S.B. Hedges (2000)
Phylogenetic relationships of xenodontine snakes inferred from 12S and 16S ribosomal RNA sequences.
Mol. Phylogenet. Evol. 14 (2000) 389&endash;402.

Vidal, N. (2002)
Colubroid systematics: evidence for an early appearance of the venom apparatus followed by extensive evolutionary tinkering.
J. Toxicol. Toxin. Rev. 21 (2002) 21&endash;41.

Vidal, N. & Hedges, S.B. (2002a)
Higher-level relationships of snakes inferred from four nuclear and mitochondrial genes.
C. R. Biologies 325: 977&endash;985

Vidal, N. & Hedges, S.B. (2002b)
Higher-level relationships of caenophidian snakes inferred from four nuclear and mitochondrial genes.
C. R. Biologies 325: 987&endash;995

Zaher, Hussam (2000)
Hemipenial morphology of the south American Xenodontine snakes, with a proposal for a monophyletic Xenodontinae and a reappraisal of colubroid hemipenes.
Bull. Amer. Mus. Nat. Hist. (No. 240): 1-168

Zug,G.R.; Vitt, L.J. & Caldwell, J.P. (2001)
Herpetology, 2nd ed.
Academic Press San Diego, London, [...]XIV + 630 pp.

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Created: 10 Feb 1996 / Last changed: 27 Dec 2002