Anatomy: Edmontosaurus had short arms, a long, pointed tail, three-toed, hoofed feet, and mitten-like hands. Its head was flat and sloping with a toothless beak, cheek pouches, and hundreds of closely-packed cheek teeth that ground up its food. It was about 42 feet (13 m) long and may have weighed up to 3.5 tons. It may have had loose skin around its nose area - some paleontologists think that it may have been able to blow up this skin like a balloon, perhaps for mating rituals or intra-species rivalry. It had a series of bumps (tubercles) running along its neck, back, and tail. Edmontosaurus was a biped (it walked on two legs) that could also walk on four legs, perhaps to graze low-lying plants.

Fossils and Name: Edmontosaurus was named by Lawrence M. Lambe in 1917 from a fossil found in Alberta, Canada. Many Edmontosaurus fossils have been found, in Alberta, Canada, and Alaska, Wyoming, Montana and New Jersey in the USA. Two mummified Edmontosaurus fossils were found in Wyoming, USA.