Identifying the biggest dinosaurs that ever lived isn’t as easy a task as you might think: sure, these giant beasts left giant fossils, but it's very unusual to unearth a complete skeleton (tiny, bite-sized dinos tend to fossilize all at once, but lumbering giants like Argentinosaurus can often be identified by only a single, massive neckbone). Here are the five winners, according to the current state of paleontological research.
1. Biggest Herbivore: Argentinosaurus
Alain Beneteau/ www.paleospot.com
Although paleontologists claim to have found bigger dinosaurs, Argentinosaurus is the biggest sauropod (four-footed herbivorous dinosaur) whose size is backed up by convincing evidence. This plant-muncher (named after Argentina, where its remains were found) measured about 120 feet from head to tail and weighed over 100 tons. Just one of Argentinosaurus' vertebrae was over four feet thick!
2. Biggest Herbivore (tie): Sauroposeidon
H. Kyoht Luterman/kyoht.com
Named after the Greek god of the ocean, Sauroposeidon was once thought to be the biggest dinosaur, but paleontologists have concluded that it was slightly lighter than Argentinosaurus, "only" about 50 or 60 tons. However, Sauroposeidon was almost certainly the tallest sauropod ever to roam the earth; its neck alone was almost 40 feet long!
3. Biggest Carnivore: Spinosaurus
Arthur Weasley
You probably thought the winner in this category would be T. Rex, but it's now believed that Spinosaurus (which had a huge, crocodile-like mouth and a sail of skin jutting up from its back) was slightly heavier. It's possible that this dinosaur's sail evolved as a way of increasing its skin area, and hence allowing it to cool down faster--yet more evidence that Spinosaurus was the king of the meat-eaters.
4. Biggest Pterosaur: Quetzalcoatlus
U.S. Government Services
Just as Sauroposeidon is named after the Greek god of the ocean, Quetzalcoatlus is named after the winged Aztec god Quetzalcoatl. This gigantic pterosaur had a wingspan of 45 feet, making it the largest creature ever to fly in the air (modern eagles included). Quetzalcoatlus almost certainly didn't flap its massive wings, but used them to glide high up in the air and swoop down for prey.
5. Biggest Plesiosaur: Liopleurodon
Adam Stuart Smith
With its long, thick, tooth-studded jaws, bulky body, and massive flippers, this aquatic reptile looked a bit like a cross between an orca and a shark. Paleontologists believe Liopleurodon attained lengths of up to 50 feet, and may have weighed over 30 tons, about the dimensions of an adult sperm whale. If this doesn’t sound impressive, keep in mind that the biggest great white sharks weigh about 3 tons, max.
