Suzhousaurus megatherioides is a large therizinosauroid theropod discovered in the Lower Cretaceous Xinminpu Group of the Yujingzi Basin, in the Jiuquan area of Gansu Province, northwestern China. It is represented by an associated partial postcranial skeleton of a theropod dinosaurFeatures of its humerus, such as strongly expanded proximal and distal ends, a well developed medial tuberosity, distal condyles expressed on the humeral cranial surface, and a hypertrophied entepicondyle, definitively establish the therizinosauroid affinities of the specimen. It differs from other therizinosauroids in having a shallow, poorly demarcated glenoid fossa with a prominent rounded and striated tumescence on the dorsomedial surface of its scapular portion, and a pubis with a strongly concave cranial margin. Cladistic analysis recovers Suzhousaurus as the sister taxon of Nothronychus mckinleyi from the mid-Cretaceous of western North America; together, they are basal members of the Therizinosauroidea, more derived than the Early Cretaceous Falcarius and Beipiaosaurus but less derived than Alxasaurus and the Therizinosauridae. Along with ˇ°Nanshiungosaurusˇ± bohlini from possibly coeval beds in the Mazongshan area of northern-most Gansu, Suzhousaurus represents one of the largest-known Early Cretaceous therizinosauroids, demonstrating that this clade attained considerable body size early in its evolutionary history.
Suzhousaurus megatherioides. Cranial (1¨C4) and caudal (5¨C8) dorsal vertebrae in cranial (1, 5), caudal (2, 6), left lateral (3, 7), and right lateral (4, 8) views; dorsal rib in cranial (9) and caudal (10) views. Scale bar equals 10 cm.
Suzhousaurus megatherioides. Right scapulocoracoid in (1) lateral, (2) medial, and (3) dorsal views; right humerus in (4) cranial and (5) caudal views; left pubis in (6) lateral and (7) medial views. Scale bar equals 10 cm.
Li, D.-Q., C. Peng, H.-L. You, M. C. Lamanna, J. D. Harris, K. J. Lacovara & J.-P. Zhang. 2007. A large therizinosauroid (Dinosauria: Theropoda) from the Early Cretaceous of northwestern China. Acta Geologica Sinica (English Edition), 81, 539-549.