NATURE’S TITANS
Which Are The 10 Largest Animals That Ever Existed? Our Biggest List Yet!
Published on September 9, 2024
Credit: Jordyn St. John
Once, true giants roamed the Earth, inhabiting a planet vastly different from the one we know today. If we could travel back in time, the world might seem almost unrecognizable. Yet, some of these colossal creatures existed not so long ago, and remarkably, a few of the largest animals to ever exist still live among us today! Let's embark on a journey through time and space to discover the 10 largest animals that have ever lived.
Blue Whale
Credit: Marvin Meyer
Surprisingly, the blue whale is the largest animal known to have ever existed. Measuring up to 100 feet in length and weighing as much as 200 tons, these gentle giants are true marvels of the ocean. Even the largest dinosaurs are dwarfed in comparison, putting the extraordinary nature of these magnificent ocean inhabitants in perspective.
Their heart alone can weigh as much as a car, and their tongue can be as heavy as an elephant. Despite their colossal size, blue whales feed primarily on tiny krill, marine crustaceans less than an inch long. To satiate their enormous bodies, blue whales have to consume up to four tons of krill daily during feeding season.
Megalodon
Credit: Nicole Avagliano
The megalodon was an ancient species of mackerel shark that dominated the seas around 23 to 3.6 million years ago. Reaching lengths of up to 60 feet, it wasn't just the largest shark but also the largest fish to ever exist. Most estimates are based on tooth size, as a complete megalodon skeleton has never been recovered. In fact, the name megalodon means "large tooth," which is fitting given that its teeth could exceed seven inches in length.
With such formidable teeth, megalodon was certainly a top predator of the seas for millions of years. It preyed on large marine animals, including whales, using its powerful jaws to deliver a bite force far greater than that of any modern shark.
Argentinosaurus
Credit: Kafai Liu
Argentinosaurus was a titanic herbivorous dinosaur that roamed the Earth during the Late Cretaceous period. While their exact size is hard to estimate due to incomplete fossilized remains, it is widely considered one of the largest dinosaurs ever found. Reaching lengths of over 100 feet and weighing up to 100 tons, it could have even measured up to the mighty blue whale.
Moreover, it is likely that this massive sauropod's size was its best defense against predators. Its long neck allowed it to reach high vegetation, while its colossal legs supported its enormous weight. They are classified as titanosaurs, a class shared with other equally massive dinosaurs such as the Patagotitan and Puertasaurus.
Quetzalcoatlus
Credit: David Clode
Quetzalcoatlus, a pterosaur from the Late Cretaceous period, had an impressive wingspan of up to 36 feet, making it one of the largest flying creatures of all time. This formidable flying reptile likely soared over prehistoric landscapes, using thermal currents to glide efficiently.
This animal likely hunted on land, feeding on small vertebrates and carrion with the help of its long, toothless beak. And when on the ground, it may have stood taller than a giraffe at over 16 feet high, towering even over contemporary Tyrannosaurus, although the latter was far more massive.
Paraceratherium
Credit: Marcus Löfvenberg
An animal right out of a sci-fi movie, Paraceratherium was a gigantic hornless rhinoceros that lived during the Oligocene epoch, around 30 million years ago. It stood about 16 feet tall at the shoulder and weighed around 20 tons.
Despite its size, this colossal animal was a peaceful herbivore that likely fed on leaves and soft plants, using its long neck to reach vegetation high in trees. Its size makes it one of the largest land mammals to ever exist.
Dreadnoughtus
Credit: Arthur Shuraev
Dreadnoughtus, another colossal sauropod dinosaur, lived during the Late Cretaceous period. Measuring about 85 feet in length and weighing at least 50 tons, it earned its name from its immense size and perceived invincibility. In fact, the name Dreadnoughtus literally means "fears nothing," and is a nod to the dreadnought, a powerful class of battleship of the early twentieth century.
Regarded as one of the most massive land animals ever, Dreadnoughtus's full potential size remains uncertain. The largest specimen discovered was not fully grown when it died, leaving open the possibility that it could have surpassed other colossal competitors like Patagotitan and Argentinosaurus.
Megatherium
Credit: Bernd Dittrich
Megatherium americanum, also known as the giant ground sloth, roamed South America during the Pleistocene epoch. Growing up to 20 feet in length and weighing as much as 4 tons, it was nothing like its modern relatives. Furthermore, Megatherium was terrestrial and primarily herbivorous, feeding on leaves, fruits, and possibly small prey.
Its massive claws and strong limbs helped it to strip vegetation and defend against predators when necessary. And despite its large size, the Megatherium is thought to have been capable of adopting a bipedal posture while standing, which allowed it to reach high-growing leaves or adopt a defensive position. Interestingly, the extinction of Megatherium around 10,000 years ago is believed to be due to a combination of climate change and early human presence on the American continent.
Leedsichthys
Credit: Jacqueline Martinez
Leedsichthys, one of the largest fish known to have existed—only surpassed by the monstrous _Megalodon_—could grow up to 54 feet in length. This gentle giant swam the Earth’s oceans during the Middle Jurassic period, feeding on tiny shrimp, jellyfish, and small fish, much like modern baleen whales.
Its first fossilized remains were discovered in the 1880s by a farmer named Alfred Nicholson Leeds, who collected large fish fossils from loam pits near Peterborough, England. In fact, its scientific name, Leedsichthys, means "Leeds' fish," derived from the Greek ichthys, meaning "fish."
Deinosuchus
Credit: Vish K
Deinosuchus, an ancient relative of modern crocodiles, lived during the Late Cretaceous period around 80 million years ago. It could grow up to 40 feet in length and weigh around 8 tons, making it one of the largest crocodilians to ever exist. Its name translates to"terrible crocodile," as with its powerful jaws and massive teeth, Deinosuchus was a formidable predator, capable of taking down even large dinosaurs.
Interestingly, fossil evidence suggests that despite its massive proportions, Deinosuchus bore a strong resemblance to its modern (and smaller) relatives. It featured large, robust teeth adapted for crushing, and its back was covered with thick, hemispherical osteoderms—armor-like bony structures found in most crocodilians.
Giant Squid
Credit: Meressa Chartrand
While most of the colossal creatures on this list are long gone, there are a few exceptions. The giant squid, scientifically known as Architeuthis, is one of the largest living invertebrates. These deep-sea dwellers can grow up to 43 feet in length, with some estimates suggesting they may reach up to 66 feet. Their long tentacles, equipped with suckers lined with sharp teeth, are used to capture prey like fish and other squid.
Despite their size, giant squids are elusive and rarely seen by humans. Most of our knowledge about them comes from specimens washed ashore or found in the stomachs of their primary predators and long-standing enemies, sperm whales.