The Therizinosaurus represents a remarkable chapter in the story of dinosaurs, challenging conventional ideas about these ancient creatures. This dinosaur stands out from many of its contemporaries, offering a unique blend of features that initially puzzled scientists. Its distinctive characteristics make it a subject of ongoing fascination.
Unveiling Its Appearance
Therizinosaurus was a large bipedal dinosaur, estimated to reach lengths of 9 to 10 meters (30 to 33 feet) and stand between 4 to 5 meters (13 to 16 feet) tall. It could weigh over 5 tons. Its body plan was distinctive, featuring a proportionally small skull atop a long neck, a robust, pot-bellied torso, and hind limbs that supported its considerable weight.
The most striking feature of the Therizinosaurus was its manual unguals, or hand claws. These claws were exceptionally long, reaching up to 50 centimeters (20 inches), making them the longest known claws of any terrestrial animal. Unlike the curved claws of many predators, Therizinosaurus’s claws were notably straight and flattened, curving sharply only at their tips. Related therizinosaur species show evidence of primitive, down-like feathers, suggesting Therizinosaurus likely had sparse feathering.
A Gentle Giant’s Lifestyle
Despite its classification within the theropod group, primarily consisting of carnivorous dinosaurs, Therizinosaurus was a herbivore. Its diet consisted mainly of leaves and twigs, which it likely stripped from trees. The large, robust body and wide torso are consistent with a plant-eating lifestyle, providing ample space for a digestive system capable of processing fibrous vegetation.
The purpose of its long claws has been a subject of scientific discussion. One prominent theory suggests they were used to pull branches and foliage within reach, allowing the dinosaur to access leaves from tall trees for high browsing. The claws may also have served as a form of defense against large predators, such as the contemporary Tarbosaurus, which shared its habitat in Late Cretaceous Asia. Some recent studies propose that the claws, especially the largest ones, might have been too fragile for aggressive combat or digging, suggesting they could have functioned as a display feature for intimidation or attracting mates. Therizinosaurus lived approximately 70 to 72 million years ago in the Late Cretaceous period, inhabiting woodlands and riparian areas of what is now the Nemegt Formation in Mongolia.