Select the snake family or subfamily and your current world region. If you don't know the family/subfamily, go to the "Find terrestrial snake by morphology (general)" page and follow the instructions.
Find terrestrial venomous snake by morphology (regional)
Selection
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Morphological identification key
| Viperinae | ||||||
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Are there several enlarged shields (generally 9) on the top of the head?
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yes |
How many ventral scales (on the belly, from the neck to the anal plate A, which covers the cloaca) are present? |
more than 170 |
Atractaspis sp. | ||
| fewer than 160 |
Causus sp. |
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| no | ||||||
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Do the lateral scales have saw-like serrated keels? |
yes | Echis sp. |
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| no |
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Are all the subcaudal scales (underneath the tail, from behind the anal plate A, which covers the cloaca) undivided? |
yes |
Do the ventral scales (on the belly) have lateral keels? |
yes |
Bitis worthingtoni (occur only in Kenya) or Cerastes cerastes (occur only in northern Sudan) |
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| no | Atheris sp. (excluding A. hindi and A. superciliaris!) |
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| no |
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What is the appearance of the region between the nasal scale N (scale on which the nostril is located) and the rostral scale R (forwardmost scale on the tip of the snout)? |
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a) Nasal scale in contact with the rostral scale or separated by a single scale. |
a |
Atheris hindii (=Montatheris hindii) or A. superciliaris (=Proatheris superciliaris) |
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b) 1 or more rows of scales separate the nasal and rostral scales. |
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| b | Bitis sp. (excluding B. worthingtoni!)
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