Top 10 World’s Largest Dinosaurs Ever

Largest Dinosaurs Ever
© Elenarts/

Written by Rebecca Bales

Updated: October 11, 2023

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Dinosaurs were massive, incredible reptiles that roamed the planet for millions of years. Although some of them were the size of chickens, like Velociraptors, others stood taller than giraffes, like Quetzalcoatlus. Before they were killed off by a devastating asteroid impact, some dinosaurs weighed 50 tons or more and grew over 100 feet long! Today, we’re going to look at the top 10 world’s largest dinosaurs ever.

Before we do that, we need to consider how we decide which dinosaurs were the biggest dinosaur ever.

Measuring the World’s Largest Dinosaur

Tyrannosaurus rex stomping through a prehistoric landscape

The T-Rex was large, but it was not close to the biggest.


For our purposes, the biggest dinosaurs ever are those that had the longest measurement from head to tail. Measuring dinosaurs by height or weight could also be useful. However, neither of those measurements is individually useful for figuring out the “largest” creature.

In some ways, the length of these dinosaurs also informs their height. After all, scientists believe many of the giant herbivorous creatures would rear back on their hind legs to reach food. Thus, their optimum height and reach would be over 100 feet despite not being that tall.

In short, we’re going to use length as the measure for the largest dinosaur. Yet, we will also offer other background information on these creatures.

The Top 10 World’s Largest Dinosaurs Ever

argentinosaurus vs blue whale

The Argentinosaurus was a massive dinosaur with a thick body and a long neck.


Before we discover the 10 world’s biggest dinosaurs ever, we must talk about inaccuracies in the available measurements.

The measurements we introduce here will most likely not be entirely accurate. Unfortunately, there is nothing we can do about that. Many dinosaurs’ fossils represent only a portion of the reptile’s large body. Oftentimes, scientists compare the recovered portion, such as vertebrae, with more complete models to estimate the dinosaur’s size.

Then, they would reasonably scale and estimate the new dinosaur’s size and weight based on that information. That’s the only data we have to offer in this case.

Other times, dinosaur fossils are believed to be one species but turn out to be another.

Simply put, this means we are going to award the title of the world’s largest dinosaur ever to the dinosaur with the greatest reasonable estimate for size.

Without further ado, let’s discover the biggest dinosaurs!

Infographic of the 10 Largest Dinosaurs Ever in the World
Supersaurus was the largest dinosaur and estimated to have been about 140 feet long.

10.  Barosaurus

Largest Dinosaurs Ever: Barosaurus lentus

The Barosaurus was once believed to be 157 feet long but was found to be actually 89 feet.


Barosaurus lentus82–89 ft13-73 tons

Until recently, the Barosaurus was believed to be the biggest dinosaur ever. The former estimates said this creature measured up to 157 feet long. However, recent studies found that the fossil remains that formed the basis of this measure did not belong to the Barosaurus. The BYU 9024 specimen was determined to belong to Supersaurus.

As a result, the known fossils of this dinosaur diminished its overall size to perhaps 89 feet or a bit longer. This dinosaur had forked bones in its tail with spikes. The tail ended with a whiplash this dinosaur was able to use its tail as a weapon. Also, this dinosaur may have reared up on its back legs to dine on plants far off the ground.

9. Antarctosaurus

3D rendering of a Brachiosaurus

The Antarctosaurus is believed to have weighed between 72 and 76 tons.

©Daniel Eskridge/

Antarctosaurus giganteus98 ft64-72 tons

The Antarctosaurus giganteus is the largest member of the genus. The first remains of this dinosaur were detailed in 1929. The incomplete fossil fragments provided a good look at the rib and vertebrae of the creature.

The fragments of the dinosaur led to a hypothetical size creation. Based on their estimates from two femurs that measured 7.7 ft in length, scientists believe that the dinosaur measured about 98 ft long and stood about 33 to 36 ft tall.

The dinosaur is believed to have weighed as much as 72 or 76 tons at its highest based on recent estimates. However, scientists have agonized over the length and weight of this dinosaur. Some have even claimed that it was 100 ft long and 50 tons in weight. It’s the perfect example of a dinosaur shrouded in mystery.

8. Puertasaurus

Largest Dinosaurs Ever: Puertasaurus reuili

Puertasaurus fossils were discovered in Patagonia, Argentina.


Puertasaurus reuili98 ft50-61 tons

The only fossils found from a Puertasaurus reuili came from the Late Cretaceous Period. They were discovered in southwestern Patagonia, Argentina. This dinosaur was the first titanosaur with preserved cervical vertebrae.

Paleontologists believe this dinosaur was about 98 feet long and weighed approximately 50 to 61 tons or up to 122,000 lbs.  

Its recorded dorsal vertebra, which measures 5 feet 6 inches, is the broadest of any recovered vertebra fossil. The size and shape of this vertebra indicate that this one may have had a very wide rib cage. Therefore, it may have been heavier than other species from the same period.

Scientists believe that this dinosaur had a more flexible neck than most. Therefore, it was able to eat a broader diet than those with a stiff neck since it could reach different places.

7. Sauroposeidon  

Largest Dinosaurs Ever: Sauroposeidon proteles

The Sauroposeidon was believed to have weighed between 88,000 and 112,000 pounds.


Sauroposeidon proteles92-112 ft44-66 tons

The Sauroposeidon proteles lived in Texas, Oklahoma, and Wyoming during the Early Cretaceous period. When it was first discovered, people believed that it was the largest dinosaur of all time. Part of the reason for this immediate attention was the amazing height of Sauroposeidon, resulting from its immense neck.

This dinosaur that may have been up to 112 feet long may have stood up to 55 feet tall if it could stick its head straight up. Which means, it is considered to be the tallest dinosaur. Also, the colossus weighed between 88,000 and 112,000 pounds.

The first fossils were found in Oklahoma in 1994, and they were put in storage by the University of Oklahoma because they believed they were petrified wood. It was not until six years later that a graduate student discovered the error and realized that they were some of the largest dinosaur bones ever recovered.

Also, the tallest dinosaur may have weighed as much as 132,000 pounds. If you want to see Sauroposeidon proteles dinosaur tracks, head to Dinosaur Valley State Park, near Glen Rose, Texas. The state even made the Sauroposeidon its official state dinosaur.  

6. Diplodocus

3D rendering of Diplodocus

The Diplodocus had scaly skin

©Daniel Eskridge/

Diplodocus hallorum89-115 ft11-25 tons

The Diplodocus hallorum lived at the end of the Jurassic Period. This dinosaur is known for its long tail, long neck, thick body, and powerful legs. This dinosaur is believed to measure up to 115 feet in length.

Interestingly, this is also quite a light dinosaur compared to some of the others. Even though it grows 115 ft in length, it only weighs perhaps 28,000 to 50,000 pounds.

Another interesting fact about this species was that its skin was scaly. The evidence of preserved scales helped scientists learn more about how the dinosaurs of the era looked and how their bodies functioned.  

5. Ruyangosaurus

Largest Dinosaurs Ever: Ruyangosaurus giganteus

A sketch of the Ruyangosaurus giganteus, a very large dinosaur living the China in the Cretaceous period.

©Shrongo / CC BY-SA 3.0 – Original / License

Ruyangosaurus giganteus81-115 ft55 tons or more

The R. giganteus is a relative newcomer to the world of large dinosaurs. This dinosaur was only discovered in China and described in 2009. Information about this species is somewhat scarce. However, scientists have provided some good estimates about its size and when it lived.

Currently, it’s believed that this dinosaur is from the Cretaceous era. Two estimates about this dinosaur’s size exist. One source says it was probably about 35 meters long, and another says about 24.8 meters long. In other words, the creature was probably between 81 and 115 ft long.

Furthermore, estimates claim that this dinosaur was between 37.5 tons and 55 tons. All in all, this was a rather long dinosaur that probably stood over 30ft tall. Still, the limited fossils from this specimen make it hard to be certain about its size.

4. Patagotitan

Patagotitan Mayorum

The Patagotitian is believed to have been 121 feet long and to have weighed up to 85 tons.

©Oleg Senkov/

Patagotitan mayorum102-121 ft57-85 tons

Experts believe that Patagotitan mayorum, also called Titanosaur, lived during the Late Cretaceous period, approximately 97 million years ago. Based on the species description, this dinosaur measured about 121 feet long and could have weighed upwards of 85 tons. However, modern takes on the species have tempered that estimate.  

Patagotitan are just one species of Titanosaur and it is one of the largest land mammals that have ever been discovered. If you put it into perspective, that is about 7 African elephants. The Patagotitan was in fact a herbivore and there’s actually little known about it’s diet. Although, we can speculate it ate leaves and fruit from tall trees.

Unlike many dinosaurs, where scientists have to do a lot of guesswork, 84 fossils have been recovered in Argentina’s Patagonia region. They are on display at the American Museum of Natural History.

3. Argentinosaurus

Largest Dinosaurs Ever: Argentinosaurus huinculensis

Fossils of the Argentinosaurus were discovered close to Plaza Huincul, Argentina.


Argentinosaurus huinculensis98-115 ft72-110 tons

The Argentinosaurus huinculensis lived during the Late Cretaceous period. However, fossils of this dinosaur were not found until 1987. A farmer working his fields unearthed the fossils near Plaza Huincul, Argentina.

As with many others, there is a lot of debate about this animal’s size. Some people believe them to be 98 feet in length. Other sources insist this dinosaur was 130 feet long. The same inconsistency in estimates can be found in the dinosaur’s weight. Some believe it weighed as little as 144,000 pounds while others think he tipped the scale at more than 220,000 pounds.

It’s important to mention that Argentinosaurus is one of the largest land animals in history. Researchers have recovered many quality fossils, so they can say with some confidence that this animal was this size.

This reptile is the reason we have the disclaimer at the beginning of this article. In some respects, this was the biggest thing to roam the land, but other higher estimates have been made. We’re going to respect the wisdom of experts in the field.

2. Maraapunisaurus

Largest Dinosaurs Ever: Maraapunisaurus fragillimus

Maraapunisaurus is a genus of sauropod dinosaur from the Late Jurassic Morrison Formation of western North America.

©Paleonychus – Original / License

Maraapunisaurus fragilimus99-131 ft87-132 tons

The Maraapunisaurus may be one of the world’s largest dinosaurs, but humans have even less evidence of this creature than usual. In fact, only one fossil from the Maraapunisaurus fragillimus has ever been discovered. Unfortunately, that fossil was lost.

Based on contemporary measurements and field notes about the fossil, Gregory S. Paul, a researcher renowned for his dinosaur restorations, suggested that the Maraapunisaurus was about 131 feet long at its maximum. This is smaller than the original estimates that suggested the Maraapunisaurus could have been 200ft long.

Although the descriptions of the dinosaur’s fossil indicate that it could have been the biggest of all time, the lack of details, accurate documentation, and good measurements make it unfair and somewhat impossible to name this creature the biggest ever.

We won’t know where to correctly place this creature until a new fossil specimen is found.

1. Supersaurus

Largest Dinosaurs Ever: Supersaurus vivianae

The Supersaurus was the world’s largest dinosaur and is estimated to have measured about 140 feet long.


Supersaurus vivianae105-138 ft35-40 tons

Supersaurus is first in the top 10 world’s largest dinosaurs. Fossils of the Supersaurus vivianae have been found in Colorado and may have been found in Portugal. This animal lived about 153 million years ago. In the past, experts believed that this species could be up to 141 feet long, but they have downgraded their opinion to 105-138 feet.

Either way, Supersaurus was the world’s largest dinosaur. However, it did not have the massive weight that one might expect from such a long creature. The fossil specimens for Supersaurus are in good shape, so recent estimates for the dinosaur’s length have surpassed 120 feet or 40 meters, and may have been closer to 140 feet in length.  

Thus, this is the creature about which we have the best data and has the best examinable claim.

Updates to the Top 10 World’s Largest Dinosaurs

A couple of brachiosaurus in a marshy spot

The Brachiosaurus could reach plants up to 30 feet off the ground thanks to their long necks.


New fossil evidence and the analysis of old evidence will likely lead to changes in our ranked list. As recently as last year, Barosaurus was potentially the largest dinosaur to ever walk the planet. Now, it’s barely in the top 10.

And another example of shifting information — there is one almost mythical dinosaur that could knock the Argentinosaurus out of its #3 spot in size if more evidence is found. Fossils of the Bruhathkayosaurus, which were found in India, included a limb, hip, and tail, and estimates of its size were over 115 feet long and a weight of 80 tons. However, the fossils, which were written about in 1987, have since disintegrated.

We will attempt to update this list as new information becomes available.

Summary of the Top 10 World’s Largest Dinosaurs Ever


Some dinosaurs may have had feathers, thus the theory that birds evolved from certain dinosaurs types.

©Daniel Eskridge/

1Supersaurus105-138 ft / 35-40 tons
2Maraapunisaurus99-131 ft / 87-132 tons
3Argentinosaurus98-115 ft / 72-110 tons
4Patagotitan102-121 ft / 57-85 tons
5Ruyangosaurus81-115 ft / 55 tons or more
6Diplodocus89-115 ft / 11-25 tons
7Sauroposeidon92-112 ft / 44-66 tons
8Puertasaurus98 ft / 50-61 tons
9Antarctosaurus98 ft / 64-72 tons
10Barosaurus82–89 ft / 13-73 tons

What Is the Smallest Dinosaur in the World?

On the other end of the scale, the smallest dinosaur is one that was discovered very recently – in 2020 – and is only the size of a bee hummingbird. Its name is the Oculudentavis khaungraae. Oculudentavis means “eye-tooth-bird.” This name was chosen because the fossil, found encased in 99-million-year-old amber, appears to have large eyes and lots of teeth.

There is one problem with this name: the dinosaur is not a bird! Wrongly identified at first, within a year scientists found a better fossil and realized that this two-inch dinosaur is actually a reptile! The new name is Oculudentavis naga in honor of the Naga people of Myanmar, where the amber was found. (The genus name, having been recorded, was not changed.) The first fossil contained only a skull, but the second fossil shows some skeleton and a skull. As we said above, new discoveries happen all the time, so stay tuned!

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About the Author

Rebecca is an experienced Professional Freelancer with nearly a decade of expertise in writing SEO Content, Digital Illustrations, and Graphic Design. When not engrossed in her creative endeavors, Rebecca dedicates her time to cycling and filming her nature adventures. When not focused on her passion for creating and crafting optimized materials, she harbors a deep fascination and love for cats, jumping spiders, and pet rats.

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