The 10 Biggest Land Animals of All Time

Amphicoelias fragillimus, Diplodocus, Sauroposeidon

• Though the fossil record is fragmentary, some paleontologists believe that Amphicoelias fragillimus was the biggest land animal that ever lived. Based on the few fossilized bones that have been found, it was estimated to be from 130 to 200 feet long and weigh 135 tons. It lived in what is now the Western United States. Since there were no flowering plants when Amphicoelias lived, it most likely ate cycads, ferns, rushes and similar plants.

  Diplodocus is next, at 115 feet long and 125 tons. It lived in the same region as Amphicoelias. Indeed, many sauropod fossils were discovered in this area, and paleontologists have wondered how all these very large animals could have coexisted for such a long period of time without degrading their environment.

  The next largest animal was Sauroposeidon, which was 112 feet long and weighed 50 to 60 tons.

Supersaurus, Argentinosaurus, Barosaurus

• Supersaurus was 110 feet long and weighed 35 to 40 tons. It is probably the same animal as Ultrasaurus. Argentinosaurus was 98 feet long and weighed 90 to 100 tons. It's different from its cousins because its fossils were found in Argentina. At the time when Argentinosaurus lived, South America was an island continent. Barosaurus was 82 feet long and weight from 38 to 48 tons and had an extremely long neck. Like the other sauropods, it had massive legs like columns to support its great weight.

Brachiosaurus, Apatosaurus, Epachthosaurus

• Brachiosaurus was about 82 feet long and weighed about 38 to 48 tons. The popular apatosaurus, which used to be called brontosaurus and is one of the most recognizable dinosaurs along with tyrannosaurus and stegosaurus, was about 75 feet long and weighed 25 tons. Its new name means "deceptive lizard" and came about because scientists believed that the bones in the underside of its tail actually belonged to a marine lizard. Epachthosaurus (heavy lizard) was 51 to 68 feet long, and came from what's now Patagonia in South America.

Extinction

• All of these animals were far far larger than the largest elephant, rhinoceros or hippopotamus living today. Sauropods first appeared in the late Triassic Period, from around 220 million years ago and were widespread by the Late Cretaceous period, about 70 million years ago. They all died out, like the other dinosaurs, in the great extinction that happened about 60 million years ago.