Therizinosaurs were a group of theropod dinsosaurs that are recognized as having long necks, small heads, big claws, and eating plants. They have been found in North America and Asia. They evolved in the early Cretaceous, although one dinosaur called Eshanosaurus from the early Jurassic of China is suspected to be a therizinosaur. If that is true, than therizinosaurs may have evolved earlier than we thought) and lasted to the K/Pg Extinction.