It’s a giant snake.
That’s what most people think when it comes to Titanoboa cerrejonensis, meaning “Giant Boa from the Cerrejón”. It looks like something straight out of a straight to video B-list horror movie; an animal that is very familiar but scaled up to gargantuan proportions. The giant extinct shark Megalodon has this same problem and I think just labelling animal like these two as “just an oversized [insert animal here]” doesn’t tell the whole story. In this blog article I shall look at the truth about this giant snake, and find out just what kind of animal it really was.
Now the first thing that documentaries and any paleo-obsessed person will tell you about Titanoboa is that it was very big. They are not exaggerating! The study (published in 2009) that first described Titanoboa estimated that it grew up to 13 metres long; almost double the length of The Reticulated Python, the largest living snake. If that wasn’t enough other palaeontologists argue that Titanoboa could have grown even larger, to lengths approaching 14.5 metres! For comparison that’s longer than a bus (as most extinct animal books will boldly state) and a Titanoboa would have no problem rearing up to tower over a human if it had ever encountered one. Titanoboa lived 60-58 million years ago during a time known as the Palaeocene period. Its size gives Titanoboa the record as the largest land animal that we know of from this time, and also the title of the largest land predator since the demise of the non-avian dinosaurs, which only happened 7 million years before Titanoboa existed.
The first fossil that was identified as belonging to a Titanoboa was a single vertebrae unearthed from a coal mine in the Cerrejón region in Northern Colombia in 2007. This wasn’t actually the first fossil ever found of it, but was the first that was recognised as belonging to a new animal. The snake identification was made due to the fossil vertebrae’s similarities to modern snake vertebrae. From just this one bone, palaeontologists were able to deduce several key bits of information about Titanoboa. Firstly, the vertebrae was very similar to those found in modern day boa constrictors and Anacondas, suggesting that these snakes are Titanoboa’s closest living relatives (and that is reason for the “boa” part of Titanoboa!). Secondly the vertebrae was massive, almost twice the size of an Anacondas, and by scaling with measurements from them the authors of the 2009 study were able to obtain their 13 metre length estimate. After this find, further fossil expeditions to the Cerrejón have unearthed further remains including up to 100 further vertebrae and a partially complete skull. The skull is particularly exciting as snake skulls are delicate and don’t usually preserve well in the fossil record.
So how would this supersized snake have lived? Well the answer is that it would have had a similar lifestyle to that of modern Anacondas, just on a larger scale. Like all Boas, Titanoboa would not have possessed venom. Instead it would have hunted in the same way as modern day Boa Constrictor snakes; wrapping its body quickly and tightly around its prey and using its large body muscles to squeeze it hard. This action would break bones and cause suffocation as the prey’s windpipe and chest cavity were constricted. Once its prey had been subdued Titanoboa would then open its dislocatable jaws very wide and swallow it whole, sometimes taking hours to do so. Animals on Titanoboa’s menu included the numerous species of crocodilians and turtles that also inhabited the Cerrejón region. Like modern day Anacondas Titanoboa would’ve spent a lot of its time in water, swimming around the lakes and rivers of its very hot, very humid rainforest home. In these rivers lived another major source of food for the snake; fish. The skull of Titanoboa was found to contain more teeth than those of a modern boa, and the the teeth themselves were more loosely attached to the skull. This would’ve allowed the snake to more easily grab and hold onto wriggly, slippery prey. Furthermore fossils have been unearthed from the Cerrejón dirt of lungfish that grew up to 3 metres long! This large fish would have certainly provided a filling meal for a Titanoboa.
To be honest what fascinates me about Titanoboa is not just the snake itself, but the ecosystem that it was a part of. 58 million years ago the Cerrejón was a unique place because it was dominated by reptiles. Indeed journey back only 7 million years and this statement would still be true! But these reptiles weren’t like the non-avian dinosaurs. Instead they belonged to more familiar families. For example living alongside the supersized snake that was Titanoboa was Carbonemys; a prehistoric turtle that could grow as large as a small car! There were also multiple species of dyrosaurs; a now extinct group of crocodilians (the reptile group that contains modern day crocodiles and alligators) which could grow up to 6 metres long in large species like Acherontisuchus. The long standing theory as to why these reptiles could grow as large as they did is that in the Palaeocene period the world was going through what is known as a “thermal maximum”. This is a global warming event that resulted in the worlds average surface temperature was much higher than today, and this heat, combined with 50% higher Carbon Dioxide levels, created a warm and very humid world that was so hot that there were no polar ice caps! To get an idea as to what the Cerrejón region was like imagine the Amazon Rainforest but even hotter, more humid and more waterlogged. These were favourable conditions for reptiles, who could absorb the highly abundant heat and use it to keep themselves active and fuel their internal biochemistry for longer periods at a time. This heat also meant they could generate more energy for growing larger sizes. In fact Titanoboas size has been used by a team of palaeontologists led by Jason Head (Head et. al. 2009) to estimate that the average yearly temperature of the Cerrejón 58 million years ago was between 30-34 Degrees Celsius. This was definitely a place where packing some suntan lotion, loose clothing and insect repellent would have been necessary! But its not just temperature that produced these giant reptiles. After the K/T extinction event (which took place 65 million years ago and wiped out 70% of all life on earth – casualties included the non-avian dinosaurs, pterosaurs and marine reptiles), many ecosystems were left vacant and open for the survivors to claim them. Furthermore mammals at this time had, in general, yet to grow large enough to fill the large animal niches available. As a result other groups were able to claim these open niches for themselves. In some parts of the world these were birds, with some growing taller than a man, and in the Cerrejón it was the reptiles, with Titanoboa taking the job of top predator.
The Palaeocene was undoubtedly a unique and weird period in earth’s history, and Titanoboa is a prime example of what can happen when an extinction event and favourable conditions creates evolutionary openings. While some people will be glad that this snake isn’t around anymore (and it certainly wouldn’t help cure anybody’s ophidiophobia!) I personally wish it were possible to see a living, breathing Titanoboa. It is a paleontological icon for a reason; it’s not just a giant snake, it’s THE giant snake.
Head, J., Bloch, J., Hastings, A. et al. Giant boid snake from the Palaeocene neotropics reveals hotter past equatorial temperatures. Nature 457, 715–717 (2009). https://doi.org/10.1038/nature07671
NOTE: This paper has had its critics, with a few other papers being published (e.g. Sniderman 2009, Denny, Lockwood & Somero 2009) offering arguments that dispute the claim that the large size of Titanoboa can be used to estimate the temperature of the Cerrejón region 58 million years ago
Gugliotta, Guy, “How Titanoboa, the 40-Foot-Long Snake, Was Found”, Smithsonian, www.Smithsonianmag.com, https://www.smithsonianmag.com/science-nature/how-titanoboa-the-40-foot-long-snake-was-found-115791429/
Bloch, Jonathan, “Titanoboa”, Florida Museum, www.floridamuseum.ufl.edu, https://www.floridamuseum.ufl.edu/100years/titanoboa/