Classification: Theropoda, Therizinosauroidea, Therizinosauridae.
Genus: Therizinosaurus (“Scythe Lizard”)
Species: T. cheloniformes
Despite the large size of these claws, recent studies have shown that they were not likely used for any mechanical function, and were probably used for display. Smaller relatives of Therizinosaurus may have used their claws for digging or hooking vegetation, but stress tests on the claws of Therizinosaurus show that they were not well-suited for these tasks.
Despite being a theropod (a group traditionally associated with meat-eaters), Therizinosaurus is thought to have been a plant-eater. Its long neck helped it reach high plants, and its beaked mouth probably aided in cropping vegetation.
Therizinosaurus belonged to a group of unusual dinosaurs called the therizinosaurs, of which it was the largest known member. It had a relatively small head with a beak-like mouth, a long neck, and a large stomach. It was likely feathered over much of its body, and walked on two legs.
Its most striking feature were the three large claws on each forelimb. The arms of Therizinosaurus each measured nearly 8 feet in length, with claws that are estimated to have been up to two or even three feet long.
Length: Up to 10 meters (33 feet) in length
Therizinosaurus lived in the Late Cretaceous Period, approximately 70 million years ago.
It likely lived in a heavily wooded area with plentiful rivers and deltas, with a temperate climate.
Therizinosaurus shared its environment with long-necked sauropod titanosaurs, as well as the ornithomimosaur Deinocheirus, which like Therizinosaurus was known for its long arms and claws, as well as an unusual body shape. It also lived alongside duckbilled dinosaurs like Saurolophus, and ankylosaurs like Tarchia and Saichania.
The main apex predator in the environment was the tyrannosaurid Tarbosaurus. It may have preyed upon Therizinosaurus, although it would have had some trouble attacking an adult fully grown Therizinosaurus due to its immense height.