Iguanodon (pronounced: Ig-WAN-oh-DON) were the largest herbivore dinosaur that lived during the early Cretaceous about 132 to 100 million years ago. These dinosaurs had a horny toothless beak and tightly packed cheek teeth. They had no front teeth, but had strong teeth about 2 inches long in the side of its jaw which it probably used them to nipped and grind cycads and other primitive plant.
Iguanodon can weight up to 4-5 tons, grow up to 10 meters long and 5 meters tall. From footprints and fossil remains, palaeontologists were able to identify that they had four fingers plus a conical thumb spike on each hand. It was believed that the thumb spikes that range for 2-6 inches long may have been used for defence purposes or in obtaining food.
This type of dinosaur had a flat, stiff tail and three-toed hind feet with hoof-like claws. When compared with its arm, their legs were much larger. They were able to run on two or walk on four legs at a relatively fast speed.
Fossil finding of around 30 skeletons found in a Belgian coal mine suggest that Iguanodon lived in herds. Other fossil remains were found throughout Europe, possibly North America, and China.
Iguanodon (pronounced: Ig-WAN-oh-DON) were the largest herbivore dinosaur that lived during the early Cretaceous about 132 to 100 million years ago. These dinosaurs had a horny toothless beak and tightly packed cheek teeth. They had no front teeth, but had strong teeth about 2 inches long in the side of its jaw which it probably used them to nipped and grind cycads and other primitive plant. 
This type of dinosaur had a flat, stiff tail and three-toed hind feet with hoof-like claws. When compared with its arm, their legs were much larger. They were able to run on two or walk on four legs at a relatively fast speed.