Meet The Gigantic Beast That Weighed as Much as a House!

The largest land animal that ever lived was dreadnoughtus, a sauropod that weighed an astounding 54 tons. That’s as much as a house! It’s named for a type of early 20th-century battleship, the first of which was the HMS Dreadnought. Read on to find out more about this dinosaur that moved over land like an unstoppable warship.

Scientific Classification of Dreadnoughtus

Description & Size

Dreadnoughtus is a sauropod dinosaur discovered in Argentina in 2005. Fossils of this dinosaur are more complete than any other species of large sauropod. In life, dreadnoughtus was about 85 feet long and weighed an estimated 54 tons. It stood about 20 feet high at the shoulder. Based on its bone structure, paleontologists believe it held its neck out horizontally. If it did raise its neck up vertically, to reach leaves on a high tree, for example, it could reach a dizzying 35 feet off the ground! Measuring from the head all the way to the tip of the tail, dreadnoughtus was 85 feet long. That’s the same as the distance between bases on a standard-sized baseball diamond. And it’s entirely possible that this beast would have been even larger at full adulthood, as the two specimens that have been recovered were juveniles.

Comparison to Other Animals

This chart shows how dreadnoughtus compared in size with other large animals of the past and present. Note that the African bush elephant is currently the largest land animal in the world. The moose is the largest land animal in North America. The blue whale is the largest animal ever to have lived. It is much larger than any dinosaur of the land or sea ever discovered.

Habitat and Diet

Dreadnoughtus lived about 77 million years ago, which places it in the Late Cretaceous Period. During this period the world was warmer and more humid than it is today, so much so that there were no polar ice caps. Dinosaurs even roamed across the forests of what is today Antarctica.

Dreadnoughtus was a herbivore that could have eaten from the highest treetops. In view of its size and the enormous weight it needed to maintain, though, it likely would have eaten any vegetation within reach. Some of the plants that lived during this geologic epoch were cycads, conifers, ferns, and ginkgoes. Angiosperms, or flowering plants covered the landscape.

Coexisting Dinosaurs

Other fossils recovered in the same formation as the dreadnoughtus were the puertasaurus, the orkoraptor, the austrocheirus isasii, and the talenkauen, as well as turtles and crocodiles. In view of its enormous size, it is unlikely that an adult dreadnoughtus would have any natural predators. The recovered fossils do have teeth marks that are likely from a megaraptoran predator. It appears, though, that the specimens recovered were buried by mud during a flood, though. The teeth marks on the bones could have been made by scavaging after they were dead rather than by a predator that killed them.

Why Did Dreadnoughtus Go Extinct?

Most researchers assume that dreanoughtus went extinct during the Cretaceous-Paleogene extinction event that happened about 66 million years ago. It was the result of a large asteroid or comet that impacted the planet at what is today the Yucatan Peninsula of Mexico. It altered the Earth’s climate, causing three-fourths of all living things to go extinct. Sea turtles, crocodiles, and small mammals were among the lucky few to survive this apocalypse.

What would our world be like today if dreadnoughtus and similar massive animals had not gone extinct? It’s difficult to imagine how human beings could have coexisted with them in large numbers. Agriculture would have been impossible, as no wall could be strong enough to keep them from eating entire fields and orchards. Even if they were not aggressive toward people, imagine how they would block traffic, smash their heads curiously into the windows of upper-floor kitchens, or flatten buildings. Only by migrating to protected places like islands or inaccessible mountain valleys could humans hope to build a civilization where their work was not quickly destroyed. All in all, dinosaurs like dreadnoughtus are best enjoyed in fossil form!