Meet The Colossal Dinosaur That’s Hard to Imagine

Largest Dinosaurs Ever: Puertasaurus reuili

Written by Kyle Glatz

Updated: March 17, 2023

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Dinosaurs were the largest land animals in history. While dozens of species were very large, a few of the dinosaurs, like the titanosaurs, were so large that it’s hard to imagine what they looked like. One particular colossal dinosaur was among the largest ever discovered. For a while, the reptile seemed like it may be the largest dinosaur ever discovered.

Learn about this massive dinosaur including how big it grew, when it lived, and how it ranks compared to some of the other biggest dinosaurs to ever live!  

What Is the Colossal Dinosaur?

Puertasaurus was a large sauropod

was a massive sauropod.

The colossal dinosaur is called Puertasaurus reuili, and it’s a bit of a newcomer in the scientific world. After all, its fossils were first officially described in 2005. Unlike other dinosaurs that receive their name from a certain quality they have, like the “different lizard” Allosaurus, Puertasaurus reuili was named for the two people who discovered the specimen named Pablo Puerta and Santiago Reuil.

The dinosaur is known by four vertebrae fossil specimens of the creature. That’s not much to go on, but scientists know that this was an exceptionally large dinosaur. Still, the colossal dinosaur is literally hard to imagine because scientists recovered so few fossils of the large reptile.

The most recent estimates state that Puertasaurus measured about 98 feet long, down from an initial estimate of 131 feet long. Furthermore, scientists believe that the dinosaur weighed about 50 to 61 tons, about 100,000 to 122,000 pounds when it was fully grown.

Puertasaurus was a large sauropod that belonged to the Titanosauria clade that features massive dinosaurs. This herbivorous dinosaur was similar to other giant sauropods with a small head, long neck, large body, four powerful legs, and a very long tail. Scientists believe that this creature walked at a speed of about 7.6 miles per hour, making it one of the slowest-moving dinosaurs in existence.

Also, Puertasaurus was unique in that the creature had an incredibly wide rib cage. This part of their body may have measured about 16 to 26.2 feet wide That’s large enough for people to walk through!

Was Puertasaurus the Largest Dinosaur Ever?

Largest Dinosaurs Ever: Supersaurus vivianae

Supersaurus is a genus of diplodocid sauropod dinosaur that lived in North America during the Late Jurassic period.

While Puertasaurus was a very large dinosaur, it was neither the largest nor the heaviest dinosaur to exist. Puertasaurus weighed about 122,000 pounds at its highest modern estimate, and it grew about 98 feet long.

Currently, scientists believe that the longest dinosaur to ever exist was Supersaurus. While this dinosaur only weighed about 70,000 to 80,000 pounds, it grew anywhere between 128 and 137 feet. That measure is longer than three school buses! This creature’s neck alone could measure almost 50 feet, allowing the herbivore to reach the highest vegetation possible.

According to modern estimates, the heaviest dinosaur to exist was Argentinosaurus. This monstrous creature weighed somewhere between 110,000 and 220,000 pounds! In other words, it could almost double the weight of Puertasaurus.

So, while Puertasaurus was an incredibly long and heavy dinosaur, it probably wasn’t the largest or heaviest. For a time, though, scientists believed that this could be the largest dinosaur ever discovered.

The initial estimates for the size of this dinosaur concluded that it measured between 115 and 131 feet long and weighed upwards of 110 tons. That would have made it very similar in size to Argentinosaurus, which could have measured upwards of 130 feet long. Recent estimates have shortened Puertasaurus and made it lighter, though.  

When Did Puertasaurus Live?

Dinosaur Asteroid

may have lived until the end of the dinosaurs.

Puertasaurus lived during the Late Cretaceous Period. Knowing the precise age of this creature is difficult because only one set of fossils has been recovered so far. These fossils were found in Patagonia, Argentina. More specifically, they were located in the Cerro Fortaleza Formation.

These rocks were traced back to the final two stages of the Cretaceous Period. That’s why scientists know that the dinosaur lived during the Campanian Epoch or the Maastrichtian Epoch. The Campanian Epoch lasted from 83.6 million years ago to about 72 million years ago. The Maastrichtian Epoch lasted from 72.1 to 66 million years ago, the end of the Cretaceous Period as a whole.

Based on that information, the Puertasaurus died at some point between 86.6 years ago and 66 million years ago. That makes sense because non-avian dinosaurs were wiped out by the Cretaceous-Paleogene extinction event about 66 million years ago.

Yet, scientists don’t know when the Puertasaurus first appeared. If other specimens of this dinosaur were to be discovered, paleontologists would have a better idea of when they lived. Until then, we only know that one of these dinosaurs lived at some point between 86 and 66 million years ago.  

Where Were Fossils of This Colossal Dinosaur Recovered?

The fossils of Puertasaurus were first discovered in Patagonia, Argentina in 2001. The samples included four vertebrae, and they were formally described in 2005. When the dinosaur lived, this area would have been a large, forested area and rife with other large dinosaurs like Dreadnoughtus, a dinosaur that lived at the same time and places as the colossal dinosaur.

Where Can You See Fossils of Puertasaurus?


Very few fossils of the colossal dinosaur exist, and recreations are probably not accurate.

Unfortunately, very few fossils of Puertasaurus exist. That means the creature is very hard to imagine. So, it’s not a dinosaur with many fossils, casts, or statues. In other words, digital resources are the best place to see this dinosaur.

The original fossils of the Puertasaurus are currently housed in Museo Carmen Funes in Argentina. The museum houses many collections of dinosaurs that lived in the area and abroad. They even have a recreation of a T-rex in the museum.  Still, the fossils of this creature are not particularly widespread or available to the public.

Puertasaurus is an interesting dinosaur. It’s one of the largest, heaviest dinosaurs to ever exist. Any new evidence about this dinosaur could greatly alter the size of the creature and help clarify when it lived.

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About the Author

Kyle Glatz is a writer at A-Z-Animals where his primary focus is on geography and mammals. Kyle has been writing for researching and writing about animals and numerous other topics for 10 years, and he holds a Bachelor's Degree in English and Education from Rowan University. A resident of New Jersey, Kyle enjoys reading, writing, and playing video games.

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