6 of the Largest Prehistoric Animals Ever (Weighed More than 10 Elephants!)

Most of the largest animals ever to roam the earth lived millions of years ago. These large prehistoric animals walked the earth. Today, our largest animals swim in the ocean. The blue whale, a mammal, can grow to be 100 feet long (that’s nearly three school buses!) and weigh as much as 200 tons. Yet this behemoth pales in comparison to the prehistoric creatures—dinosaurs—that once dominated the landscape. Let’s dive into the largest prehistoric animals.

Massive Prehistoric Dinosaurs

Millions of years ago, animals even larger than the blue whale were walking the earth. Paleontologists called these creatures dinosaurs, and we only know about them because of fossils. Fossils are remnants, impressions, or traces of an animal or plant from a past geologic age preserved in the Earth’s crust. What we know about dinosaurs today has been pieced together by paleontologists and others who have found or dug up fossils.

The largest of these has changed over time as new fossils are found every year. However,

Additionally, experts have located three distinct species of these giant dinosaurs over time. They found the first of these three species in 2000 and another even bigger one in 2005. Finally, experts found the biggest of the three in 2013.

Needless to say, with new fossils found every year the debate of which dinosaur grew the largest will rage for a long time to come!

Titanosaurs, Cretaceous Period (145 to 66 Million Years Ago)

Titanosaurs were the largest of the dinosaurs that scientists have ever discovered. They lived during the Earth’s Cretaceous Period, and recently, paleontologists have uncovered Titanosaur fossils on every continent. For example, in 2017, someone found the fossilized remains of a Titanosaur in Argentina, dating back about 100 million years.

1. Patagotitan mayorum—A 70-Ton Sauropod

Between its discovery in 2013 and its official naming in August 2017, Patagotitan mayorum was known as a Titanosaur because of its enormous size. This large prehistoric dinosaur had a long neck, stood on all four legs, lived on land, grew to about 120 feet tall, and weighed up to 70 tons. Scientists believe they were the largest terrestrial animals that ever existed, thanks to a thigh bone that was discovered that measured an astounding 8 feet in length.

The species was present between 100 million and 95 million years ago. Paleontologists have classified Patagotitan mayorum as an herbivorous sauropod. It likely fed on leaves and used its long neck to reach into tall trees.

2. Argentinosaurus—An 85-Ton Herbivore

In 1987, an Argentinian farmer discovered a piece of petrified wood as big as a man. Analysis of the wood identified it as part of an unknown dinosaur species. This giant would later be named Argentinosaurus huinculensis. Unfortunately, people have only ever found fragments of Argentinosaurus skeletons, but scientists believe that this dinosaur was 98 feet long and weighed 85 tons. Still, earlier estimates were at a much more significant size, but scientists adjusted these to the current proportions. It is suggested that Argentinosaurus lived in groups of 20, foraged in areas of dense vegetation, and consumed leaves and fruits from conifers.

3. Dreadnoughtus—A 65-Ton Land Dweller

Dreadnoughtus schrani fossils were discovered in an Argentinian rock formation in 2014. Scientists estimated that Dreadnoughtus was 30 feet tall and had a 37-foot neck. Their approximate height is estimated at 85 feet with a weight of 65 tons, making this one of the most gigantic land dwellers ever. Initially, only two incomplete fossils of Dreadnoughtus were found in 2013. Scientists estimated their size using a more complete skeleton containing parts of a skull and teeth. Dreadnoughtus was an herbivore and likely used its long neck to reach branches and leaves on tall trees. In addition, scientists think Dreadnoughtus may have used its tail as a weapon against predators.

4. Giganotosaurus carolinii—A 15-Ton Predator

Nearly 100 (99.6) million years ago, a massive flesh-eating dinosaur roamed around modern-day Argentina. Fossils of Giganotosaurus carolinii were unearthed in El Cochon, Argentina, in 1993. Giganotosaurus should not be confused with Gigantosaurus, an herbivore from the Great Britain region. Giganotosaurus carolinii weighed 10 tons and was 45 feet tall. Studies show that Giganotosaurus may even have reached a weight of 15 tons. This weight makes Gigantosaurus bigger than the Tyrannosaurus rex, whom scientists previously believed to be the biggest carnivorous dinosaur.

Giganotosaurus shared the Earth with titanosaurs like the Dreadnoughtus and Patagotitan and likely hunted them. Giganotosaurus is closely related to the Allosaurs. Like its Allosaur cousins, Giganotosaurus walked upright. It had short forearms with three fingers and claws on each forepaw. Scientists estimate that Giganotosaurus could run up to 31.3 miles per hour. This speed makes it faster than Tyrannosaurus, which was estimated only to run at 25 miles per hour. Of course, there remains considerable debate about the speed of these massive dinosaurs.

5. Hatzegopteryx—A Giant of the Skies

Two-hundred fifty pounds may not sound like much compared to the 85-ton Argentinosaurus, but just consider that the heaviest flying animal in the world today weighs just 45 pounds.

During the late Cretaceous period, a massive giant dominated the skies over Hatzeg Island, an area of land that was separated from mainland Europe. People uncovered the first fossil of Hatzegopteryx in the Hatzeg Basin, later finding more in regions of Romania. This sizeable flying pterosaur was named Hatzegopteryx thambema. Hatzegopteryx stood 18 feet tall, weighed approximately 250 pounds, and had a wingspan of 40 feet.

This pterosaur had an extremely heavy skull and was exceptionally strong. Scientists believe that Hatzegopteryx behaved like the storks and herons we see today. It likely caught and ate smaller dinosaurs and fish. Hatzegopteryx also probably had to take several jumps to launch itself into the air due to its weight.

6. Quetzalcoatlus—A 500-Pound Pterosaur

Seventy million years ago, a giant flying dinosaur stalked the marshlands of the modern Rio Grande. Quetzalcoatlus northropi was one of the largest pterosaurs ever to fly. This mammoth creature had a wingspan of 39 feet and stood 16 feet tall. Weight estimates on the Quetzalcoatlus place it in the region of 400 to 500 pounds. Experts unearthed fossils of this massive pterosaur in 1971 in Texas. However, they know little about its diet, but scientists speculate that it may have caught fish or scavenged for carrion.

Quetzalcoatlus likely acted like today’s herons, prowling waterways to snag fish. Experts don’t know much about how this giant pterosaur launched itself into the air, but it is suspected that they did running jumps like the Hatzegopteryx. Alternatively, scientists think they might have jumped from cliffs to fly.

Summary of the 6 Largest Prehistoric Animals Ever