These sauropods are among the largest land animals ever discovered, and include the Sauroposeidon at 60 ft. tall, and 60 tons, and the Brachiosaurus, at 40 feet tall and 80 tons, and the Ultrasauros at 100 ft. long and 80 tons. The biggest carnivorous dinosaurs were the Giganotosaurus at 47 ft. The Tyrannosaurus Rex was the second largest dinosaur carnivore at 50 ft. long and 6 tons. The largest Pterosaur or flying reptile was the Quetzalcoatlus with a wingspan of 36 ft. The smallest dinosaur is a theropod called Microraptor found recently in China.
Dinosaurs are extinct giant lizards.
Dinosaurs are a group of extinct lizards, who now exist only in fossil form. Image Karen Carr. Dinosaurs became extinct about 65 million years ago, about the same time as a giant asteroid collided with Earth, in the Yucatan peninsula, off the coast of Mexico. The Pterosaur is an extinct order of flying reptiles, which included the Pterodactyl from the Lower Jurassic to late Mesozoic. Fossilized remains found in strata reveal that the flying mechanism of a Pterodactyl was a large membrane between the body, and a greatly developed fourth digit.