Tetrapod Zoology

Help identify the snake. Please.


Can you identify this South American snake? The photo comes courtesy of Paul Nicholas, who spotted the snake (which was about 1 m long) while it was crossing a river below the Great Falls and King George Falls in the (mostly unexplored) upper Essequibo region of Guyana. The strange-looking lumps are water drops. Paul’s guides were not able to identify the snake – can you? I confess I haven’t tried too hard… field guides on Guyanan snakes are thin on the ground round here…

But, with its enormous eye and parallel dorsal strikes, the animal (which is a ‘colubrid’) should be identifiable (if, that is, it belongs to a known species).

For previous Tet Zoo posts on snakes see…


  1. #1 neil
    January 12, 2010


  2. #2 John Conway
    January 12, 2010


  3. #3 Sarkas
    January 12, 2010

    I agree, looks like a sipo snake (Chironius), they are common in the Guyanas…

  4. #4 Jared
    January 12, 2010

    …damn, I’ve got nothing…
    The eyes don’t look right to be Chironius and the scales look keeled in this animal.

    About the eyes; Chironius has ocular scales that do not rise above the parietal scales as this one seems to have.

  5. #5 Darren Naish
    January 12, 2010

    I’m pretty sure it’s not a Chironius. Chironius species have larger scales, don’t they? Not that I’ve seen a Chironius, you understand 🙂

  6. #6 neil
    January 12, 2010

    Damn. Well, as long as I’m demonstrating my ignorance of tropical American snakes, how about Dendrophidion?

  7. #7 Bob Michaels
    January 12, 2010

    It`s a Colubridae, thats 635 of all species of snakes are in this family Could be a new species, right now it`s a cryptid. Put a call into Karl Shuker.

  8. #8 Bradley Fierstine
    January 12, 2010

    Shuker is a smart guy but not sure he is an expert on obscure Latin American colubrids!

  9. #9 Jared
    January 12, 2010

    Yea, Darren, Chironius have 5 rows of scales, this one has 6, they’re also not keeled as this one looks to be.

    I might be able to do better with a higher res image of the head, but without being able to see the labial scales, the closest I can go is “in the dumping ground*, maybe.”

    *the “dumping ground” being Colubridae.

    Addendum: I looked through my book of Central American snakes and had nothing, so it’s something probably specific only to South America; if that helps any.

  10. #10 Alan Kellogg
    January 13, 2010

    That’s Melvin. He went missing in 2005 and people have been looking for him ever since. His aunt Edna died just three months after he disappeared and left him a fair amount of cash in her will. People are going to be surprised he showed up in Guyana.

    What species? Can’t tell you. Melvin was adopted into a family of pit vipers through less than legal means, and so the paper work is a mess. The judge on the case ordered the court records sealed.

  11. #11 Tim Morris
    January 13, 2010

    That looks ALOT like an Australian Green Tree Snake at first glance, what with the blue stripes. It’s also a little reminiscent of a garter snake.

  12. #12 Sven DiMilo
    January 13, 2010

    If I wanted to ID a South American snake, I’d ask Laurie Vitt.

  13. #13 Moro
    January 13, 2010

    It’s cute, whatever it is…

  14. #14 Donald J Kaleta
    January 13, 2010

    For general interest to Herpetology,snake enthusiast. There is availible a simple to use and cost efficient process for flat mounting the shed skins from snakes that is a valuable tool for snake identification. Search http://WWW.USPTO.GOV and issued PATENT 4,147,826 to Inventor Donald J Kaleta April 3,1979.

  15. #15 Katkinkate
    January 13, 2010

    It is cute, with its big eyes and stubby nose. I haven’t a clue what it is, but it’s definitely not an anaconda or a boa (the only 2 S.Am snakes I know anything at all about).

  16. #16 Dartian
    January 14, 2010


    it’s definitely not an anaconda or a boa (the only 2 S.Am snakes I know anything at all about)

    Actually, there are several species of both boas and anacondas (and, strictly speaking, anacondas are also boas) in South America. Darren has explained that before; please click on the link to his ‘Not two, not three, but FOUR anacondas’ post at the end of this article.

  17. #17 retrieverman
    January 15, 2010

    I’m dying to know the answer.

    Surely some herpetologist knows what it is.

  18. #18 Darren Naish
    January 15, 2010

    I’m still asking around, but at the moment I agree with Neil that Dendrophidion is looking pretty likely. However, while there are species that look similar in terms of proportions/eye shape/scalation etc. (e.g., D. percarinatus), I can’t find any species that has the greyish ‘striped’ dorsum and yellow ventral surface of the Essequibo snake shown here.

  19. #19 Philippe Kok
    January 15, 2010

    Hi Guys,

    A friend of mine sent me the URL of this page because I am working on the Guyanese herpetofauna for a while now.
    I strongly believe this is a Chironius, probably carinatus.
    You might have been misled by the size of the eye, which is quite large indeed. But the specimen is estimated to be around 100 cm (a rough estimation because it was not collected), which means it is probably between 60 cm and 100 cm, thus still a young individual. In Chironius species, young individuals have noticeably larger eyes than adults.
    Also, the “stripes” or the “keels” some of you see on the back/flanks of this animal are due to the fact that this snake is inflating its body, probably because it is quite nervous to meet people (as most Chironius), which means that what you see are not rows of lighter scales or some kind of keels, but skin. Chironius species are aggressive and often display that kind of behavior.
    The quality of the photograph does not really allow any speculation on cephalic or body scutellation, but really I am pretty sure this is a Chironius.

    Hope this helps.



  20. #20 Darren Naish
    January 15, 2010

    Hi Philippe – many thanks for your expertise; your opinion is much appreciated. Unfortunately, Paul was not able to get a better photo, so I’m afraid that this is all that we have. Google shows me that some individuals of Chironius carinatus are indeed yellow on the side of the back of the head and on the throat, so I’m inclined to think that this is an acceptable identification after all. Unless anyone comes up with a better ID, this is what we’re going with!

    And well done Neil for perhaps getting it right first time round 🙂 Is there no end to your talents?

  21. #21 neil
    January 15, 2010

    Wow, did I just win the internet? Snap.

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