However , new , well-preserved finds such as `` Alxasaurus '' in 1993 and `` Beipiaosaurus '' in 1996 provided details about the bird-like pelvis , feet , and skulls of primitive members and helped confirm that segnosaurids belonged to the same group of theropod dinosaurs as `` Therizinosaurus '' ( and were therefore renamed therizinosaurids ) , and that therizinosaurs were , more specifically , advanced , herbivorous maniraptoran theropods .
New , well-preserved finds such as `` Alxasaurus '' in 1993 and `` Beipiaosaurus '' in 1996 provided details about the bird-like pelvis , feet and skulls of primitive members . This helped confirm they belonged to the same group of theropod dinosaurs as `` Therizinosaurus '' and that therizinosaurs were , more specifically , advanced , herbivorous maniraptoran theropods .