Identifying the biggest dinosaurs that ever lived isn't an easy task. Sure, these giant beasts left giant fossils, but it's very rare to unearth a complete skeleton.
Ten Biggest Dinosaurs
Here's a look at the 10 biggest dinosaurs according to the current state of paleontological research.
1. Biggest Sauropod: Argentinosaurus
Argentinosaurus is the biggest sauropod whose size has been backed up by convincing evidence. This gigantic plant-muncher measured about 120 feet from head to tail and may have weighed over 100 tons.
2. Biggest Sauropod: Sauroposeidon
Named after Poseidon, the Greek god of the ocean, Sauroposeidon was once thought to be the biggest dinosaur of all time, but paleontologists have since concluded that it was slightly lighter than Argentinosaurus. However, Sauroposeidon was almost certainly the tallest sauropod ever to roam the earth.
3. Biggest Carnivore: Spinosaurus
You probably thought the winner in this category would be T. Rex, but it's now believed that Spinosaurus was slightly heavier, weighing in at 7 or 8 tons.
4. Biggest Pterosaur: Quetzalcoatlus
Quetzalcoatlus is named after the winged Aztec god Quetzalcoatl. This gigantic pterosaur had a wingspan of up to 45 feet, making it the largest creature ever to fly.
5. Biggest Pliosaur: Liopleurodon
With its long, thick, tooth-studded jaws, bulky body, and massive flippers, this pliosaur looked a bit like a cross between an orca and a shark. Paleontologists believe Liopleurodon attained lengths of 40 to 50 feet, and may have weighed 20 to 30 tons.
6. Biggest Hadrosaur: Shantungosaurus
The hadrosaurs, or duck-billed dinosaurs, were the most common herbivores of the late Cretaceous period. Shantungosaurus was the biggest hadrosaur yet known, about 50 feet long and anywhere from 15 to 50 tons.
7. Biggest Raptor: Utahraptor
Utahraptor weighed in at a whopping 1,500 pounds and was a full 20 feet long.
8. Biggest Therapsid: Moschops
The Moschops looked a bit like a cross between a cow and a frog, with its blunt, bovine face and splay-footed, four-legged posture. This odd creature may have reached lengths of up to 20 feet and weights of a few tons, making it the biggest land animal of its time.
9. Biggest Crocodile: Sarcosuchus
Better known as "SuperCroc," the 40-foot-long Sarcosuchus weighed about 8 tons.
10. Biggest Ichthyosaur: Shonisaurus
The ichthyosaurs were a group of sleek, hydrodynamic, and often quite large aquatic reptiles that thrived from the late Triassic to the middle Cretaceous periods. No ichthyosaur came bigger than the 50-foot-long, 30-ton Shonisaurus, which looked like a cross between a blue whale and a dolphin. Thanks for watching. To learn more, visit About.comd