Early Cretaceous – 115 – 108 Mya
Montana, Wyoming, Oklahoma, Texas, Idaho, Utah, Maryland
Length: 7 meters (23 feet)
Height: 4 meters (13 feet)
Weight: 1,814 kg (4,000 lb)
Although lacking spikes or armor, an adult Tenontosaurus would not have been easy prey for a predator like Deinonychus. It was large enough to break the bones of a smaller predator!
Tenontosaurus had an unusually long, broad tail and its back was stiffened with a network of bony tendons, hence the name Sinew Lizard. Browsing on low growing vegetation, the powerful beak and angled cutting surfaces of its teeth meant that Tenontosaurus could consume not only leaves but wood and possibly fruit.