Alxasaurus (meaning "Alxa lizard") was a therizinosaur theropod that lived during the Lower Cretaceous, about 112 to 100 million years ago. Like its near relatives, it was herbivorous. It was about 13 ft (4 m) long and weighed about 800–900 pounds (350 to 400 kg). Five incomplete fossil skeletons have been found in Mongolia.