<==o Elaphe
   |-- E. bairdi
   |-- E. bimaculata
   |-- †E. buisi
   |-- E. carinata
   |-- E. climacophora
   |-- E. conspicillata
   |-- E. davidi
   |-- E. dione
   |-- E. emoryi
   |-- E. erythrura
   |-- E. flavirufa
   |-- E. flavolineata
   |-- E. gloydi
   |-- E. guttata (Linnaeus, 1766) (viljakäärme)
   |-- E. helena
   |-- E. hohenackeri
   |-- †E. kansensis
   |-- E. leonardi
   |-- E. lineata
   |-- E. longissima (pensaskäärme)
   |-- E. maculata
   |-- E. mandarina
   |-- E. moellendorffi
   |--o E. obsoleta (rottakäärme)
   |  |-- E. o. obsoleta
   |  `-- E. o. quadrivittata (keltainen rottakäärme)
   |-- E. perlacea
   |-- E. persica
   |-- †E. pliocenica
   |-- E. porphyracea
   |-- E. prasina
   |-- E. quadrivirgata
   |-- E. quatuorlineata
   |-- E. radiata
   |-- E. rufodorsata
   |-- E. scalaris
   |-- E. schrenckii
   |-- E. situla
   |-- E. subradiata
   |-- E. taeniura
   `--+-- †E. nebraskensis Holman, 1964
      `-- E. vulpina


Reference(s):

    Holman, J. A., 1987: Herpetofauna of the Egelhoff site (Miocene: Barstovian)
of North-Central Nebraska.
–Journal of Vertebrate Paleontology: Vol. 7, #2, pp. 109-120

    Lahti, S., Malmström, K. K., Koli, L., Leikola, A., Syrjämäki, J.
& Lahti, J., 1980:
Zoo, Suuri Eläinkirja 5: Kalat, sammakkoeläimet, matelijat.
--Werner Söderström Osakeyhtiö, Porvoo-Helsinki-Juva, 1980.
    Original publication [in French]: Beauté Du Monde Animal:
IX Reptiles/Amphibiens & X Poissons
Rizzoli Editore, Milano 1968.

    Parmley, D. & Holman, J. A., 1995:
Hemphillian (Late Miocene) snakes from Nebraska,
with comments on Arikareean through Blancan snakes of midcontinental North America.
–Journal of Vertebrate Paleontology: Vol. 15, #1, pp. 79-95

    Uetz, P., Etzold, T. & Chenna, R.,
 1995-2000: Family Colubridae (Colubrids).
–iNet: The TIGR Reptile Database
 [former EMBL Reptile Database]: http://www.embl-heidelberg.de/~uetz/families/Colubridae.html