<==o SERPENTES [Ophidia] (käärmeet)
   |?- †Pachyophiidae
   `--+?- †Coniophiidae
      |?- †Palaeophidae
      |-- †Dinilysiidae
      |?- †"Pachyrhachidae" sensu Caldwell & Lee, 1997
      |-- †Madtsoiidae
      `--+?-o SCOLECOPHIDIA (sokkokäärmeet)
         |  |-- Leptotyphlopidae (matokäärmeet)
         |  `--+-- Typhlopidae (sokkokäärmeet)
         |     `-- Anomalepididae
         `--o ALETHINOPHIDIA
            |-- †Lapparentophidae
            `--+-- †Simoliophidae
               |--o ANILIOIDEA (telakäärmeensukuiset)
               |  |== Cylindrophidae ()? [paraphyletic]
               |  |-- Aniliidae (telakäärmeet)
               |  `-- Uropeltidae (kilpipyrstökäärmeet)
               `--o MACROSTOMATA
                  |-- Loxocemidae
                  `--+-- Xenopeltidae
                     `--+?- †"Pachyrhachidae" sensu Tchernov, Rieppel, Zaher, Polcyn & Jacobs, 2000
                        `--+-- Pythonidae (pythonit)
                           `--+-- Boidae (boat)
                              `--+== Tropidophiidae: Ungaliophiinae
                                 `--+-- Bolyeriidae [BOLYERIOIDEA]
                                    `--+-- Tropidophiidae: Tropidophiinae 
                                       `--+--o ACROCHORDOIDEA (käsnäkäärmeidensukuiset käärmeet)
                                          |  |?- †Nigerophidae
                                          |  `-- Acrochordidae
                                          `--o COLUMBROIDEA (myrkkykäärmeet)
                                             |?- †Anomalophidae
                                             |?- †Russellophidae
                                             |--o PROTEROGLYPHA
                                             |  |-- Atractaspididae [+Aparallactinae]
                                             |  |-- Colubridae (tarhakäärmeet) [possibly paraphyletic]
                                             |  `-- Elapidae (myrkkytarhakäärmeet)
                                             `--o OPISTHOGLYPHA
                                                `-- Viperidea (kyykäärmeet)

Reference(s):

    Caldwell, M. W. & Lee, M. S. Y., 1997: A snake with legs from the marine Cretaceous
of the Middle East.
–Nature: Vol. 386, 17 April, pp. 705-709

    Scanlon, J. D., & Lee, M. S. Y., 2000: The pleistocene serpent Wonambi
and the early evolution of snakes.
–Nature: Vol. 403, 27 January, pp. 416-420

    Tchernov, E., Rieppel, O., Zaher, H., Polcyn, M., J., & Jacobs, L., L., 2000:
A fossil snake with limbs.
--Science: Vol. 287, 17 March, pp. 2010-2012

    Rage, J. C. & Werner, C., 1999: Mid-Cretaceous (Cenomanian) snakes from Wadi Abu
Hashim, Sudan: The earliest snake assemblage.
--Palaeontologia Africana: Vol. 35, pp. 85-110.

    Zaher, H. 1998: The phylogenetic position of Pachyrhachis
within snakes (Squamata, Lepidosauria)
--Journal or Vertebrate Paleontology: Vol. 18, #1, pp. 1-3