The Green Anaconda (Eunectes murinus) has earned its reputation as a massive serpent, but whether another snake surpasses it depends entirely on the metric used. Determining the biggest snake requires clarifying how we define “bigness,” as the answer changes if we consider the animal’s pure length versus its total body mass.
Defining How Snakes Are Measured
Herpetologists primarily use two distinct measurements to quantify a snake’s size. The first is total length, which is a straight-line measurement from the tip of the snout to the end of the tail. The second is the snake’s mass or weight, which represents its volume and bulk.
These two metrics rarely point to the same species as the largest because snake body shapes vary widely. Some species are long and slender, while others are relatively shorter but possess immense girth. Mass is often considered the more reliable proxy when comparing overall size, as it accounts for the animal’s three-dimensional bulk.
The Green Anaconda The Heavyweight Champion
The Green Anaconda (Eunectes murinus) holds the title of the world’s largest snake by mass, making it the heavyweight champion among modern serpents. Its immense size is attributed to its thick, muscular body, which can exceed 30 centimeters (12 inches) in diameter. Due to this bulk, it is capable of overpowering large prey, including capybara, caiman, and jaguars.
While average adult females typically reach lengths of around 5.5 meters (18 feet), their weight sets them apart. A healthy adult can easily weigh over 100 kilograms (220 pounds). Scientifically verified specimens have demonstrated masses of over 250 kilograms (550 pounds) and lengths up to 9 meters (30 feet). The Anaconda’s semiaquatic lifestyle in the swamps and slow-moving rivers of the Amazon and Orinoco basins in South America allows it to support this incredible weight, as the water helps bear its mass.
The Reticulated Python The Longest Snake
If “bigger” is defined strictly by length, the snake that surpasses the Anaconda is the Reticulated Python (Malayopython reticulatus). Native to Southeast Asia, this species is recognized as the longest snake in the world. While the Green Anaconda is bulky, the Reticulated Python is built for length and is notably more slender.
The typical adult Reticulated Python reaches lengths between 4.8 and 6 meters (16 and 20 feet), but it is the maximum recorded lengths that secure its title. Modern experts estimate the maximum length is reliably in the range of 8 to 9 meters (26 to 29.5 feet). Even at comparable lengths, a large Reticulated Python may weigh up to 159 kilograms (350 pounds), making it significantly lighter than an Anaconda of a similar length. This difference highlights the trade-off between the Anaconda’s girth and the Python’s impressive linear dimension.
Extinct Snakes That Dwarf Modern Species
While the Reticulated Python is the longest living snake, there are extinct species that dwarf both it and the Green Anaconda in both length and mass. The most famous prehistoric giant is Titanoboa cerrejonensis, which lived approximately 58 million to 60 million years ago during the Paleocene Epoch. Discovered in Colombia, its size is estimated based on the dimensions of its fossilized vertebrae.
Titanoboa is estimated to have reached an average body length of roughly 13 meters (42.7 feet). Its massive size means it was not only longer but also substantially heavier than any snake alive today, with estimated weights reaching 1,135 kilograms (2,500 pounds). This extinct serpent shows that the physical limits of snake size were once far greater.