Therizinosaurus

Therizinosaurus Temporal range: Late Cretaceous, 70 Ma PreЄ Є O S D C P T J K Pg N ↓
Fossil forelimbs
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Order:	Saurischia
Suborder:	Theropoda
Family:	†Therizinosauridae
Genus:	†Therizinosaurus Maleev, 1954
Species:	†T. cheloniformis
Binomial name
Therizinosaurus cheloniformis Maleev, 1954

Therizinosaurus (/ˌθɛrɪˌzɪnoʊˈsɔːrəs/; 'scythe lizard', from the Greek therizo meaning 'to reap' or 'to cut off' and sauros meaning 'lizard') is a genus of very large theropod dinosaurs. Therizinosaurus comprises the single species T. cheloniformis, which lived in the late Cretaceous Period (late Campanian-early Maastrichtian stages, around 70 million years ago), and was one of the last and largest representatives of its unique group, the Therizinosauria. Fossils of this species were first discovered in Mongolia and were originally thought to belong to a turtle-like reptile (hence the species name, T. cheloniformis – "turtle-formed"). It is known only from a few bones, including gigantic hand claws, from which it gets its name.

Though the fossil remains of Therizinosaurus are incomplete, inferences can be made about their physical characteristics based on related therizinosaurids. Like other members of their family, Therizinosaurus probably had small skulls atop long necks, with bipedal gaits and heavy, deep, broad bodies (as evidenced by the wide pelvis of other therizinosaurids). Their forelimbs may have reached lengths of up to 2.5 metres (8.2 feet) or even 3.5 metres (11.5 feet) in the largest known specimen. Their hindlimbs ended in four weight-bearing toes, unlike other theropod groups, in which the first toe was reduced to a dewclaw. In 2010 Gregory S. Paul estimated the maximum size of Therizinosaurus at 10 metres (33 ft) in length and five tonnes in weight. They are the largest therizinosaurs known, and the largest known maniraptorans.