Titanoboa cerrejonensis, the World’s Largest Snake: Extinct Anaconda-Like Serpent Believed to Have Reached 43 Feet in Length and 2,500 Pounds in Weight

Hello Simon, Frank Indiviglio here.

Thanks for your interest in our blog.

It is really amazing, but it does seem to be clear that at one time 40+ snakes were a reality. The largest I’ve worked with was a 23-24 foot Reticulated Python, which was collected in Indonesia. The 30 foot mark is a tough one to break today, with only 1 possible 33 foot animal being seen in recent times. A friend involved in field research in Guyana , and who is well-experienced in judging snake lengths, is convinced that there are some real giants there…however, they are in deep rivers and difficult to get close to. To read more about giant snakes, please see Hunting Anacondas in Venezuela and Big Snake Meals.
Enjoy!
Best regards, Frank Indiviglio.

Hello Dassa, Frank Indiviglio here.

Thanks for your interest in our blog….well, small world. My friend is actually working on the Rupununi, and has sent me photos of anacondas in the 20-21- foot range (I need to go back and check details). The problem there is that the snakes have access to deep water all the time, and so it’s very hard to get hold of them. When I worked with them in Venezuela, it was much easier as during the dry season the snakes were often confined to rather shallow pools. The largest I encountered there (out of 500+ tagged) was just over 17 feet and 215 pounds. You can read more about that project in my article Hunting Anacondas in the Venezuelan Llanos.

My Rupununi contact is quite sure he has seen snakes nearing 25 feet in length, and that id larger ones exist it will be here or further south along deep rivers. He is very good at estimating sizes, comparing to canoe they are in , etc, but it is still a difficult prospect – even after many years of doing this, the “excitement factor” still comes into play when you see a giant anaconda swimming close by!

Please keep me posted on any tips you might come across, and I’ll do the same.

Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Dassa,

Thanks for the feedback. I’ve often wondered the same. Could be genetic variations in different populations, as is true for other animals. From what I’ve seen, however, I believe it may be due to the fact that it is harder for people to catch anacondas in rivers, and so they just live longer and grow larger. They are hunted in many places, for meat, skins, medicinal purposes (fat), out of fear, and so on. In llanos habitats, they are quite easy to find in the dry season…but in rivers, even within llanos, its very hard to get near them.

Prey base could play a role, but where our studies were done (central Venezuelan llanos/Apure) there was an incredible diversity/density of prey – capybara, deer, fish, smaller anacondas, birds, caiman, tegus, yet of over 500 snakes none exceeded 17.5 feet (most appeared well-fed), and no reliable reports of larger animals in recent years.

I did see one difference re diet – where birds were the likely main prey, the snake’s skins were in great shape – those feeding on caiman, capybara and deer were really banged up – broken ribs, deep scars common.

Any ideas on the topic?

Good luck, enjoy and please keep me posted on your thoughts, observations.

Best regards, Frank Indiviglio.

Hello Dassa, Frank Indiviglio here.

Good points, I agree. The habitats are so different, and human influence is a big part of it. When I first arrived in the llanos, I thought there must be some mistake – not at all what I had pictured as prime anaconda habitat (I was very wrong!). They did well on most cattle ranches, as many owners protected the animals for their own sake (Tomas Blum was inviting biologists to his ranch, El Frio, decades before such was done in most places) and also as a financial benefit – wildlife viewing tours are becoming popular. Outside the ranches, they are hard to find.

Have you been/worked/lived n these regions?

Good luck and please keep me posted.

Best regards, Frank Indiviglio.

Hello Dassa,

Thanks very much for the kind words, glad you are enjoying. Please keep an eye out for an upcoming article on an interesting new fossil discovery and for more on anacondas and other snakes. I also started reading everything I could get my hands on as a child and am still at it.

I’m extremely fortunate to have been able to work with these animals in captivity and the wild; – I hope you get to do the same. Let me know if you plan to visit Guyana, hopefully my friend’s research station will still be up and running – plenty more to see there as well; jaguars several times, giant otters and giant armadillos often, amazing array of snakes…I’m itching to go as well!

Good luck and please keep me posted.

Best regards, Frank Indiviglio.

Hello Dassa,

Nice to hear from you again….I love reading accounts like that, thanks very much!

Unfortunately, it’s very difficult to estimate a snake’s size, especially at night in the wild – even experienced field researcher’s make big mistakes; while working at the BX Zoo, I was involved in the acquisition of a Reticulated Python that had been captured in the wild and said to be over 30 feet long, photos were sent, and an experienced dealer went to have a look; no one seemed willing to wrestle the beast out of it’s enclosure, but all evidence pointed towards a monster – we purchased it and I helped measure her as soon as she arrived – just over 21 feet! Impressive, but not unusual…but great to know they are still out there, and I have no doubts that a 25 foot anaconda is possible,.

Actually one of the best documented cases of a possible 25 foot+ anaconda came out of Peru – a noted herpetologist was grabbed, the animal escaped but he got a good look – I’ll find the account t and post it when I can,

Please keep the observations coming,

Good luck and please keep me posted.

Best regards, Frank Indiviglio.

Hello Dassa,

Thanks for looking into that, sounds promising, I would love to take another trip to look at such places. Good idea on the post – I’ll pair the story with one of my own – I still carry the tooth of a large female anaconda in my wrist; it’s near some nerves and so doc left it in place…

Please keep an eye on the blog for another prehistoric snake find as well – a fossilized attack by a snake upon baby dinosaurs. I also posted about this on Twitter, within the last week or so (under findiviglio).

Good luck and please keep me posted.

Best regards, Frank Indiviglio.

Hello Joseph,

Thanks for the feedback; usually takes time to get it right, lots of variables – species, individual snake, general environment in the home, etc….only snapper and slider eggs persevere no matter what! Hope the other 2 hatch,

Good luck and please keep me posted.

Best regards, Frank Indiviglio.

Hello Dassa,

You raise a very interesting point, Thanks.

Tracking is a science, lots of fine points – length of time tracks in place, weather, substrate, and, as you mention, animal’s condition. I found a 17 foot long anaconda with a 60 pound meal in its stomach – I’m sure her track would have indicated a much larger animal. Snakes also have a great deal of “play” in their spines/connective tissue it seems.
We measured each captured snake 3 times, to assure accuracy – yet when re-captured, several were shorter, even though in good health and weight!

Good luck and please keep me posted.

Best regards, Frank Indiviglio.

Hello Tom, Frank Indiviglio here.

Thanks for your interest in our blog.

Your observation is very notable indeed! Extremely rare to come across them in the wild. It be very interested to learn if they survive and transform, and of they continue to thrive as small frogs. As you can imagine, they are a real magnet for predators, even showing up below 2-3 feet of water. Here in NY tads take 2 yrs to transform, but they might do it in one season in California…if you have a chance to check on how they’re doing from time to time, please let me know. Would be a great article in the future as well.

Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Thanks for your interest in our blog. Here’s such a mass of conflicting info out there; it’s really hard to predict. During my 20+ years at the Bronx Zoo captive female Green Anacondas regularly reached 15-17 feet; the largest I found in a mark –recapture study (E. Venezuela, llanos habitat) was just over 17 feet (500+ individuals captured); a co-worker based in Guyana regularly sees huge ones, but cannot get his hands on many due to river depth; 18 feet seems typical there. A reward offered by the Bx Zoo for a 30+ foot long snake of any species stood uncollected for nearly 100 years, and was eventually rescinded…a Retic that looked to be that size from photos actually measured 23 feet upon arrival in NYC. Many of the reports of larger animals are based on tanned skins, which can be stretched considerably once removed from the snake.

As far as I know, 2-10 feet is not typical for mature Green Anacondas, 5-10 feet would be accurate for males, females larger but vary, 8 feet might be reasonable for some populations.

A good recounting of the topic is given in the recently published Tales of Giant Snakes; a great historical account, and a wonderful read in general, in Clifford Pope’s The Giant Snakes.

A colleague and I recently came across a huge vertebrae from an animal collected in the 1930’s while going through old material at the Am Museum of Natural History; my friend may be able to extrapolate the snake’s size from that – I would need to wait until he has published his findings, but will report back when I can.

Based on what I’ve seen of their abilities to remain hidden even in very small water holes, I wouldn’t be surprised if quite large animals were living in isolated rivers, but there’s really no way to guess at what that size would be.

Please let me know your thoughts. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Nice to hear from you again. It was only a single vertebra; it appeared unusually large and thick but conversion-equation must be devised so that the size of the snake might be estimated. If my friend plans to publish this, as is likely, I would need to wait until after that happens before posting any info here. I’ll do that as soon as is possible.

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Thanks for your note; always a pleasure. The maximum upper limit for a modern snake would likely be around 30 feet, maybe a bit more. They grow extremely slowly once maturity is reached; and in the case of anacondas at least, above 16 feet they tend to add weight and girth more than length. Also, I believe there has been some work done on what the body plan can support – much like the great dane is probably as far as one could “stretch” the basic dog physiology; I don’t have articles on hand but will keep it in mind.

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Nice to hear from you again; you could never annoy me with questions or comments, this is as interesting as it gets (for me, anyway), which is why I was poking around museum cabinets stuffed with 100 yr old specimens on the day I found the bone you are referring to! Unfortunately, I don’t have the expertise to provide a decent guestimate; my colleague, who is better equipped than I to figure such things, is working on a way to do that now. He and I have seen vertebra from 19-20 foot-long-snakes, and the one we found was larger than those. I don’t think, even 100 yrs ago, there would have been a snake much over 30 feet – since this specimen was recorded and logged into the museums collection, there certainly would have been a written report about its size had it been over 30 feet…even 100 yrs ago, the Am Museum of Natural History kept careful records and published all such findings. So 20-30 feet would be safe, I believe..but no harm in hoping for surprises! I’d love to hear that you discover the next giant – keep me posted! Don’t forget about the 2 books I mentioned awhile ago, especially Clifford Pope’s..I’m sure you will enjoy.

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Thanks for the feedback…sorry, I’m not sure which comment you are referencing, but in general I would say that to mean only slightly more than 30 feet; 30 -32 feet, for example.

Please let me know if you need any further information.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Thanks for you’re the interesting info. The link to the note you mentioned did not show up in your email; however, it is very useful to see that a skin can stretch as much as 10 feet when removed from the carcass. If I recall correctly, 2 that I saw skinned stretched 3 feet or so, but the snakes were smaller that mentioned above, 15 feet or so.

Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

I admire your interest – actually, I’ve been having similar conversations with co-workers and colleagues since the ‘60’s. Unfortunately, all that has come of it has been the same type of info that you and I have covered; there’s just not enough hard data available for me to make an educated guess.

Best regards, Frank Indiviglio.

Hello Vanessa, Frank Indiviglio here.

Thanks for your interest in our blog. Here is an article on their natural history; please be in touch with any specific questions you may have.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Thanks for your note. There have been surprisingly few unusually large African rock pythons documented; there is at least 1 instance of human predation that was published (Herpetologica, I believe)., but the snake was an average-sized adult.

I think it is less likely that a giant might be out there than would be the case for green anacondas, as rock pythons generally dwell in grasslands, savannas and open habitats. They sometimes frequent forest edges, but are not deep-forest animals. Marshes might be one source of large animals, as they tend to live near water, but I know of no reliable accounts.

Rock pythons do seem to take larger prey items, comparatively speaking, than most other snakes. This may be an adaptation to the abundance/diversity of antelope (a common prey item) in their savanna habitats;; then again, it is only such meals that find their way into popular literature. Field studies of stomach contents would likely reveal a diet similar to other large snakes. Crocs and leopards have been reported on a few occasions, but neither is a typical prey item.

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Thanks; sorry if I wasn’t clear. My point was that rock pythons tens to inhabit open habitats as opposed to forest interiors. While there is a good deal of habitat that is not often explored, I’m not really sure of percentages. Actually, due in part to the long European presence in much of central Africa, most of it is better studied than is the Amazon Basin, which contains, as of now, the largest intact stretches of rainforest on the planet.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Thanks; well there are a great many theories, and as I may have mentioned I’ve heard them bandied about for decades, and others before me have repeated the same. Unfortunately, just speculation at this point… I do hope more info comes to light in the future.

Prey animal size could play a role, but certainly there are an incredible array of other factors, including the species’ evolutionary history and current genetic makeup; huge snakes have been taken from areas where they prey largely upon small animals, and zoo specimens routinely grow quite large on such diets as well, so the question needs a bit more investigation.

Comparing sizes/prey density in such huge and widely disparate areas is not really feasible absent a great deal of research….for example, I have worked along the northern fringe on the Amazon Basin, and am in touch with several long term colleagues who have spent much time in the region, and can assure you that, as in Africa, there is no shortage of large prey items, as well as dense populations…but we must factor in preferences, availability, likelihood of capture, nutritional values ….very interesting, but a lifetime’s worth of work (maybe a career path for you?).

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

The largest recorded in a peer reviewed journal, and that which is generally accepted by professional herpetologists, is 25 feet (given by Donald Broadley: (1999. The southern African python, Python natalensis A. Smith 1840, is a valid species. African Herp News. 29: 31-32)

Clifford Pope lists an animal of 32 feet in his classic The Giant Snakes (1965, A. Knopf). This account is based upon a letter sent to Mr. Pope by the person who shot the snake, and her husband, who measured it. The animal is said to have been killed near a school in Bingerville, Ivory Coast Republic, in 1932.

Equally famous herpetologist Arthur Loveridge (namesake of all those loveridgei species names) recounts that he measures a freshly removed skin at 30 feet, but believed that when alive the snake would have been nearer to 25 feet in length. It was killed along the Ngeri Ngeri River near Morogoro, in what was then Tanganyika. Check out his Many Happy Days I’ve Squandered and other books, as well as Pope’s, when you can..you’ll enjoy I’m sure

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Thanks for your interest in our blog. In order to be considered “official”, or accepted by professional herpetologists, the measurement must meet certain standards…generally, this means that animal must have been accurately measured under circumstances that can be verified (i.e reputable witnesses, photos); publication in a peer-reviewed journal is ideal. The best scenario would be for the animal to be deposited with a museum upon death. The 32 foot measurement is based on letters written by non-hepetologists years after the event, and so cannot be considered as wholly trustworthy. Therefore, most accept 25 feet as the maximum size recorded.

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

Thanks for your comment. Unfortunately, there is no way to provide accurate answers to your questions, too many factors involved. A 17.3 foot-long (wild) anaconda I handled weighed 215 pounds. The largest meal I observed was a wild anaconda of a similar size that swallowed a 60 pound deer. The largest meal I know of is a 130 pound impala consumed by an African Rock Python…please see this article for details.

Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

Best regards, Frank Indiviglio.

Hello Antonio, Frank Indiviglio here.

I admire your interest, but unfortunately I cannot add anything beyond what we’ve already discussed…anything else would be a wild guess.

Best regards, Frank Indiviglio.