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Squamata, Serpentes, Viperidae - Vipers & Relatives |
| The viperid snakes occur in both Hemispheres and range from the equator northward into cold temperate environments of Eurasia and southern Canada. Similarly, going south from the equator they extend into cold temperate habitats in South America and South Africa. However, the greatest diversity and probably the geographical origin of the family appears to be in tropical or sub-tropical Asia. Viperids have folding front fangs located on the maxillary bone. Similar to a hypodermic needle, the fangs deliver a chemical cocktail into their prey that subdues them and starts digestion before the prey have been ingested. Viperids are caenophidians, they were long thought to be some of the most derived snakes due to their venom delivery systems. However, detailed anatomical and molecular studies have revealed that vipers are basal to the Colubroidae. They are an ancient group, and a number of molecular studies have the Oriental Slug Eating Snakes (Pareatidae) or the Oriental Australian Mud Snakes (Homalopsidae) as the sister group to the Vipers. |
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Pit Vipers (Subfamily Crotalinae) occur in both the Eastern and Western Hemisphere and they are so named for the heat sensing loreal pit located between the eye and the nostril.
The Cottonmouth or Water Moccasin, Agkistrodon piscivorous (Lacepede, 1789) from the southern USA.
For more photos of Pit Vipers Click on the photo. |
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Vipers (Subfamily Viperinae) occur in Eurasia and Africa. They lack the heat sensing loreal pit between the eye and the nostril.
The Sand Viper, Cerastes vipera (Linnaeus, 1758), from Israel.
For more photos of Viperinae click on the photo. |
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| All text and photographs copyright © John C. Murphy. All rights reserved worldwide. The content of this site is made available for purposes of researching images offered for license by John C. Murphy. No image is to be copied, duplicated, modified or redistributed in whole or part without the prior written permission of JCM Natural History Photography. Email: jcm@jcmnaturalhistory.com |
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