Top 10 Biggest Dinosaurs to Have Ever Walked the Earth

This prehistoric flying animal only weighed in at about 500 pounds, meaning that serious competitive strong men could’ve bench-pressed it. Then again, based on the looks of it, such feats of strength would be ill advised. A pterosaur from the Late Cretaceous period, Quetzalcoatlus is one of the largest known animals to ever take to the skies. Though early estimates gave it a wingspan of over 50 feet, more conservative contemporary studies have reigned in that figure, suggesting 33 to 36 feet as a likely average. Although discovered in Texas, the name actually comes from the Aztec god Quetzalcoatl, which translates into “feathered serpent”. It’s hard to think of a better name for this winged monster.

Despite having a name sure to inspire nightmares, the Gigantoraptor isn’t a “raptor” in the traditional sense, but rather an oviraptorosaur that lived near the end of the Cretaceous period. It is estimated to have been more than 16 feet tall and weigh nearly two tons. Based on those measurements, one might assume that this big creature wreaked havoc on its fellow dinosaurs, but this may not have been the case, as a fossil of its jaw revealed that it actually had no teeth. Since its initial discovery in 2001, the Gigantoraptor has raised more questions than it has answered, but we can say one thing with certainty - it’s the biggest known bird-like dino discovered so far in history.

Another massive dinosaur that lived during the Late Cretaceous period, the Titanoceratops is one of the biggest horned dinosaurs ever. This beast weighed approximately 15,000 pounds, and measured roughly 22.3 feet from head to tail. Adding to both was its massive 8-foot head. Although it isn’t known for sure, it is likely that this massive head helped make males more attractive to females. You know what they say about a male titanoceratops with a big head, don’t you? ...No? Us neither. But we do know that with its discovery, the Titanoceratops also claimed the title of oldest triceratopsini.

When you think of enormous creatures, a duck likely isn’t the first, or even the hundredth thing that comes to mind. Well… meet the Magnapaulia, a platypus-looking dino that’ll make you think twice about all duck-billed creatures. Living during the Late Cretaceous period, this duck-billed dinosaur was roughly 50 feet long and weighed up to 25 tons. It’s widely believed that this dino spent the majority of its time in the water, and may have even been able to float and swim similar to elephants today.

Although it is no longer considered to be the world’s biggest carnivore, the T-Rex remains the one of the biggest theropods and apex land predators ever – which makes it still the king of the dinosaurs in the eyes of many people. While sizes vary, the T-Rex could reach up to 40 feet in length and a height of approximately 12 feet, with the largest examples weighing roughly 15 short tons. One of the most fearsome predators to ever live, the T-Rex also scavenged when the opportunity presented itself. Due to its popularity, it is one of the few dinosaurs that the public refers to by its proper scientific name.

Little is known about this dinosaur due to limited fossils, but based on the size of its humerus, Paralititan was by far one of the biggest sauropods to ever walk the earth. This behemoth was roughly 85 feet long and weighed 59 tons, and yet we would still be ignorant of its existence were it not for a fortunate mistake. Paralititan’s discovery was announced in 2001, after a grad student named Joshua Smith and his team got lost during a 1999 area survey. Despite its enormous size, this herbivore was likely hunted by large predatory dinosaurs, though taking it down would have been no small feat unless a group of predators worked together.

With a name like Giganotosaurus, you just know this dinosaur is worthy of a spot on today’s list. Etymologically-speaking, the name is inspired by Ancient Greek, and translates to “Giant Southern Lizard.” Another monster to live during the Late Cretaceous period, its exact size has been difficult to determine, although estimates believe that it weighed up to 13 tons and may have been over 40 feet long, making it bigger, on average, than the T-Rex. It could also reach speeds of up to 30 mph, which is truly remarkable when you consider its size.

Discovered in Argentina in 2005, it took paleontologists four summers to excavate the Dreadnoughtus’ remains, thanks in part to the remote location but also because of its enormous size. It is likely that this dinosaur weighed about 65 short tons, making it heavier than four T-Rex combined. It was also over 85 feet long! Although it isn’t the biggest dinosaur to ever live, it has been called the terrestrial creature with the largest known mass. Furthermore, the actual skeleton of Dreadnoughtus is one of the most complete dinosaur skeletons of its kind to ever be found. Talk about a massive find!

It’s hard to imagine a dinosaur that is both bigger and more vicious than the T-Rex, but that’s exactly what we have with the Spinosaurus. Estimates have the Spinosaurus weighing up to 20 tons and reaching up to nearly 60 feet in length. Evidence suggests that this dinosaur lived both on land and in the water, and may have even targeted the Sarcosuchus, an extinct ancient – and giant crocodile-like – reptile. The Spinosaurus even briefly stole the spotlight from the T-Rex when it served as the main villain in the third Jurassic Park film.

Before we unveil our number one pick, here are a few honorable mentions:
- Utahraptor
- Mapusaurus
- Sauroposeidon

We looked at a number of different factors when putting together this list, but the top spot could only ever go to one creature - the biggest dinosaur believed to have ever lived… the Argentinosaurus. Scientific estimates suggest that the Argentinosaurus weighed up to 100 tons and was over 115 feet long. To put this beast in perspective, consider that one of the dinosaur’s vertebra was over five feet tall. It also laid eggs comparable in size to an American football. Luckily for all other dinosaurs, the Argentinosaurus was an herbivore, although we can only imagine how much vegetation it needed to eat to survive.