Suzhousaurus

Suzhousaurus was one of the largest Early Cretaceous therizinosauroids, reaching about 6 metres (20 feet) long and weighing around 3.1 tonnes (3,100 kilograms).1

Its upper arm bone (humerus) had very expanded ends and a big entepicondyle, which helped scientists identify it as a therizinosauroid.3

Unlike more advanced therizinosaurids, Suzhousaurus's backbone was not highly pneumatized, meaning it had fewer air spaces in its vertebrae.1

Its pelvis was opisthopubic, a feature that is typical of therizinosaurids, even though Suzhousaurus was a more basal member of the group.1

Suzhousaurus had a large belly and a reduced tail, which helped it balance its heavy body.1

Feather impressions from the related Beipiaosaurus suggest that Suzhousaurus was probably at least partially feathered.1

The first specimen, FRDC-GSJB-99, was found in 1999 and includes a right humerus, shoulder bones, ten back vertebrae, and part of the pelvis, but no skull.1

A second, more complete skeleton found in 2004 includes the sacrum, tail vertebrae, a nearly complete pelvis, and both thigh bones.1