Edmontosaurus was one of the most common dinosaurs in America. It walked on two legs but could also walk on all fours and had a mouth packed with hundreds of small teeth except for the front of the jaws which had a beak.
Discovery: It was named in 1917. Two skeletons have been found with skin preserved.
Where it lived: Edmontosaurus is found throughout North America.
When it lived: Edmontosaurus lived in the Late Cretaceous of North America, about 76 to 65 million years ago.
What it ate: It ate plants. Bits of conifers have been found in its stomachs such as needles, twigs and seeds.
Weapon of choice: Edmontosaurus was big, probably too big for smaller predators but not so for T.rex. Palaeontologists believe that Edmontosaurus lived in herds and that there was safety in numbers.
Weakness: Too small and with no weaponry, Edmontosaurus was as easy as prey got for T.rex.