Tiantaisaurus

It was a medium sized dinosaur, but its exact size is not known from the fossils found. Scientists estimate an adult length of about 2 to 3 metres, as the fossils are too incomplete for a precise measurement.4

It was a plant-eater. Its group, the therizinosaurs, started out as meat-eaters but later evolved to eat plants.1

Yes, it was a feathered theropod. Many therizinosaurs are known to have had feathers, and Tiantaisaurus belonged to that group.4

It lived about 106 to 100 million years ago, during the Early Cretaceous period.4

Its fossils were found in 2005 in Tiantai, Zhejiang Province, China.1

Yes, it is a dinosaur. It belongs to the theropod group called Therizinosauridae.4

The air pockets, called pneumaticity, made its heavy body lighter and helped it move around, similar to modern bird skeletons.1

Nobody knows for sure, but the air pockets in its vertebrae helped make it less bulky and more flexible, which might have helped it move.1