Kayrasaurus

Kayrasaurus is an extinct genus of therizinosaurian theropod dinosaur known from the Early Cretaceous Yixian Formation of China. The genus contains a single species, Kayrasaurus changliensis, named in 2026 based on a nearly complete skeleton including the skull. This specimen is largely articulated, but very flattened into nearly two dimensions. The legs and most of the pelvis are unknown. With a length of 3.6 metres (12 ft) and an estimated weight of 117–274 kilograms (258–604 lb), Kayrasaurus is the largest therizinosaur known from the Jehol Biota. Like other therizinosaurs, the front of its jaws were toothless. It is unique in the small, closely packed teeth in the rest of the upper and lower jaws, bearing more teeth in the mandible than any other therizinosaur. The vertebrae in the neck are notably elongated, and the claws on the hand are large and strongly curved. Kayrasaurus is closely related to the contemporary Beipiaosaurus and Jianchangosaurus, both of which are also known from the Yixian Formation.