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Could there be a snake as large as Titanoboa still living in the Amazon? Source: Dottedyeti / Adobe Stock.

The Giant Anaconda: Is There a Monster in the Amazon?

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Everyone has heard of Big Foot and the Loch Ness Monster, but what about the Giant Anaconda? The Giant Anaconda is a fascinating creature first described by 19 th century explorer Percy H. Fawcett, but one whose existence, for now, remains unproven.

According to Fawcett and others in history who have claimed to see the Giant Anaconda, the massive prehistoric snake is over 40 feet (12 meters) long and at least a foot (30 cm) in diameter. To some, this giant snake is called Yacumama, meaning “mother of water.”

Indeed it has been described as even longer than in Fawcett’s description, reaching over 100 feet (30 meters) long and residing in the Amazon river basin. Though many claims have been made, no official sightings or evidence of this monster’s existence have come to light.

If we look at the evidence, however, the claims about this legendary creature may not be all that far off. 

All About Anacondas

Anacondas are a large group of snakes found in and around the Amazon rainforest in South America. Specifically, there are four species of anaconda: the green anaconda, the yellow anaconda, the dark-spotted anaconda, and the Bolivian anaconda. They are all members of the boa species.

The most common breed of anaconda is also the largest: the green anaconda, which has also been nicknamed the common anaconda and the giant anaconda. It is important to not confuse this reptile’s nickname with the Giant Anaconda being discussed here.

Anacondas are semi-aquatic snakes, meaning they exist on land but also excel at swimming in the rapid waters of the Amazon. Most who claim the existence of the Giant Anaconda say it hides by camouflaging in deep waters.

The green anaconda is the largest confirmed species of snake (slowmotiongli / Adobe Stock)

The green anaconda is the largest confirmed species of snake (slowmotiongli / Adobe Stock)

However, even the largest confirmed species of anaconda (the green anaconda) only reaches approximately between 10-17 feet (3-5 meters) long, though one report claims to have found one that was 23 feet (7 meters) long. Clearly this species is not the Giant Anaconda.

Reticulated pythons are longer than anacondas, reaching upwards of 20 feet in length, but are unlikely to have been the famed Giant Anaconda as they are not nearly wide or bulky enough to match the description provided by Percy H. Fawcett and others.

Green anacondas may be shorter but are a much larger snake than pythons. They can reach weights of over 500 pounds (227 kg) in some cases, while reticulated pythons only reach a bit under 200 pounds (91 kg). The girth of the anaconda distinctly separates it from the reticulated python in terms of recognition.

Percy H. Fawcett

The first record of this cryptid being described comes from Percy H. Fawcett, a British geographer and explorer of South America in the early 1900s. Fawcett’s first expedition started in 1906 in Brazil.

By 1907 he had traveled to Bolivia, where he claimed he killed a massive serpent-like creature that he found swimming in the murky waters around his boat. According to Fawcett, this snake was around 62 feet (19 meters) long and at least one foot (30 cm) in diameter. 

At the time, Fawcett had also made a number of additional statements claiming to have seen other unknown creatures including a dog with two noses and the giant Apazauca spider. Scientists largely discredited these sightings and took Fawcett’s claims lightly.

Nowadays, we know it is possible that the two-nosed dogs he had seen may have been double-nosed Andean tiger hounds (which originated in Bolivia) and the Apazauca spider may have been a Brazilian wandering spider. If these two claims may have been true, how certain can we be that the Giant Anaconda is a complete myth?

Fawcett’s expeditions continued into the 1920s. Throughout the course of his journeys, he inspired many other aspiring explorers and his expeditions even influenced the 1912 book “The Lost World” by Sir Arthur Conan Doyle.

His more credible findings also earned him a medal from the Royal Geographical Society, a UK-based society for geography, for his geographic surveying work in the Amazon. This was not some fantasist crashing around the jungle: Fawcett was a serious explorer, and his descriptions should be taken with a degree of seriousness.

Percy Fawcett in 1911 (Daniel Candido / Public Domain)

Percy Fawcett in 1911 (Daniel Candido / Public Domain)

In 1925, Fawcett’s explorations came to an unfortunate end. He, his son, and his son’s friend disappeared during an expedition to find a lost city he referred to as “Z.” It is theorized that they were either killed by Amazonian native tribes or perhaps starved to death in uncharted territory.

Their bodies were never recovered. Though tragic, his records remain valuable to this day as some of the earliest recordings of wildlife in the Amazon. The description of the Giant Anaconda in these records is not however the only one. Others claimed to have seen it as well, confirming Fawcett’s notes. 

Evidence For the Beastly Serpent

Beyond Percy H. Fawcett, some others have claimed to see the Giant Anaconda in more recent years. Mike Warner, an Irish lithographer, claimed to have found evidence of the creature using satellite photography in 2009.

A Peruvian man named Juan Carlos Palomino claims to have seen and killed an anaconda approximately 40 feet (12 meters) long during a military expedition, a truly huge snake which could not be a mere green anaconda. But beyond the individual sightings, there are also the stories in the oral history of the region.

Amazonian natives also tell legendary stories about the massive Yacumama that was over 100 feet (30 meters) long, according to the stories. With so many verbal and written accounts from the same region (a region that is known for massive snakes and great biodiversity, at that), the chance of such a creature existing at one point in history is not so far out of the question.

With the finding of a green anaconda of approximately 23 feet long in Brazil bordering Paraguay and Bolivia, the idea that longer anacondas could be hiding somewhere unexplored in the Amazon is not entirely unrealistic. Like many other creatures, it could simply be hiding in murky, unexplored waters as suggested by those who have claimed to see it.

It may also be highly skilled at camouflaging in water and trees at this point, having been able to live this long without another predator coming along to kill it or compete with it. Certainly, the thick network of waterways and the impenetrable forest would be a perfect environment for such a creature to remain hidden.

A Case of Mistaken Identity?

The issue with these firsthand accounts is that none of them are scientific. Those that have claimed to see the Giant Anaconda or even have killed one all make general estimations about the beast’s size. None of the Giant Anacondas which have been seen were ever captured, much less measured.

It can be difficult to assess the true size of a snake, especially if partially submerged (Ted / CC BY-SA 2.0)

It can be difficult to assess the true size of a snake, especially if partially submerged (Ted / CC BY-SA 2.0)

This leads to the question: how accurate are the visual assessments of those who have seen these giant snakes? It would be difficult for most people to estimate what 40 feet (12 meters) looks like without an accurate measurement comparison, especially when the creature being observed is curled and moving. It is possible that those who have claimed to see these massive beasts were simply looking at a larger-than-average anaconda and incorrectly estimated its size. 

Another aspect to consider regarding this cryptid is evolution. Throughout time, mammals and reptiles have evolved to be smaller and smaller, likely due to changing atmospheric composition and temperatures on earth and competition with humans for space and resources.

With less food and land available, only those small enough to live with less food and water will live long enough to reproduce and produce even smaller offspring. There’s also the issue with oxygen - oxygen levels have decreased on earth over the last several thousand years, making the need for large amounts of oxygen (to keep large bodies functioning) a disadvantage to large species.

Darwin’s famous survival of the fittest has certainly played out as expected when it comes to the evolution of these creatures. The world we live in now may not be able to support such a giant snake.

Because of this, it is very possible that the Giant Anaconda, Yacumama, or some similar large serpent once existed on earth. In fact, evidence of a pre-historic 50 foot (15 meter) serpent called Titanoboa was found in the early 2000s.

Paleontologists uncovered several massive vertebrae and three skull pieces belonging to the Titanoboa in South America, allowing them to piece these fossils together and learn more about the terrifying creature. According to them, the Titanoboa was the snake equivalent to the Tyrannosaurus Rex, and would have been considered the “king” of the early Amazon.

It is estimated that the Titanoboa was approximately 2,500 pounds (1,130 kg), roughly the same as an adult black rhino, and killed its large prey via constriction. To this day, the fossilized remains of the Titanoboa are the largest found remnants of any snake species on earth. 

A Different World

According to the scientists that pieced Titanoboa together, the giant serpent was likely able to thrive during the Paleocene epoch due to the much higher temperatures on earth at that time. With the snake being cold-blooded, hotter temperatures allowed it to thrive and actively compete with surrounding massive species.

Laguna Yacumama in Peru, where the monster is said to live (Eduardo Dios / CC BY-NC-SA 2.0)

Laguna Yacumama in Peru, where the monster is said to live (Eduardo Dios / CC BY-NC-SA 2.0)

The Titanoboa is now known as an early ancestor to modern-day anacondas and boa constrictors, making even more sense behind the concept of the Giant Anaconda. With anacondas still being massive in size and having ancestral DNA stemming back to Titanoboa, it could still be possible for an anaconda to grow beyond our current records if it were able to live long enough. 

Issues with the theory that Titanoboa or a similar snake still exists relate back to the changes that earth has experienced since the Paleocene epoch. Since the time of the Titanoboa, multiple ice ages have occurred. With drastically cooler temperatures than what is typical for this massive snake, it is possible it was unable to thrive in the environment of the ice age and eventually died off.

There is also the fact that the earth on average temperature is several degrees cooler than it was during the Paleocene epoch. Titanoboa would have had to not only survive the ice age, but also adapt to this overall temperature change with all other ancient species in order to survive.

Ultimately, the history of the earth’s climate works against the idea of Titanoboa, the Giant Anaconda, or Yacumama still existing today.

Could the Monster be Out There?

Though there have been few sightings of the Giant Anaconda in history, the truth of its existence remains blurry. Changes in the earth’s climate and fossilized remains of Titanoboa point towards the Giant Anaconda being extinct or simply a myth.

At the same time, personal sightings and anomalies in existing anaconda sizes suggest these massive reptiles could still be lurking in the deep somewhere in the Brazilian or Bolivian Amazon. That is if these personal sightings are accurate and not exaggerated or inerrant, which they have a high probability of being.

Ultimately, we may never uncover the full truth about the Giant Anaconda. Evidence points to the existence of a massive prehistoric ancestor to anacondas and boas, but little to no scientific evidence supports its current existence on earth.

Could this monster be out there? (Dottedyeti / Adobe Stock)

Could this monster be out there? (Dottedyeti / Adobe Stock)

However, explorations of the Amazon are still ongoing and research continues for those interested in uncovering the Amazon’s deepest secrets. To this day, the Amazon is still not fully explored and scientists are continually discovering more about the region and the biodiversity and indigenous tribes that still reside there.

In fact, researchers recently discovered that the Amazon was once home to millions of more people than previously known. Perhaps some of these natives had once come into contact with the Yacumama or its relatives. We can only hope that as research continues more evidence for the existence of the Giant Anaconda will someday be brought to light. 

Until then, you decide: is this monster of the Amazon more than just a myth? 

Top Image: Could there be a snake as large as Titanoboa still living in the Amazon? Source: Dottedyeti / Adobe Stock.

By Alexis Bishop


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Lex Leigh is a former educator with several years of writing experience under her belt. She earned her BS in Microbiology with a minor in Psychology. Soon after this, she earned her MS in Education and worked as a secondary... Read More

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