New therizinosaur species discovered
A nearly complete skeleton of a therizinosaur, named Kayrasaurus changliensis, was found in the Yixian Formation in Liaoning, China. This discovery is challenging previous understanding of the Jehol fauna from the Lower Cretaceous period, a time when many early birds and feathered dinosaurs lived.Largest therizinosaur in the region
The Kayrasaurus changliensis specimen is over 3.6 meters long and weighed between 117 and 274 kilograms. This makes it the largest therizinosaur found in this ecosystem, more than 1.6 times bigger than the previously known Beipiaosaurus inexpectus.Unique anatomical features
Kayrasaurus changliensis had over 77 tiny teeth, a long neck, and a claw with an elevated rim, a feature not seen in other therizinosaurs. Its skull also had an unusually wide opening near the snout and a two-branch tip on the nasal bones.Ecological roles of therizinosaurs
Researchers suggest that the Jehol fauna may have had two distinct ecological niches among therizinosaurs. One group, including Beipiaosaurus and Kayrasaurus, may have used a powerful bite, while others like Jianchangosaurus and Lingyuanosaurus might have been better at running and using their forelimbs for feeding.Impact on dinosaur classification
The discovery of Kayrasaurus changliensis has filled gaps in the understanding of therizinosaur anatomy and led to a reevaluation of Beipiaosaurus inexpectus. It also suggests the existence of two subclades within the Therizinosauridae, based on the shape of their hand claws, highlighting how new findings can reshape scientific classifications.
