Therizinosauria

Therizinosaurus (; meaning 'scythe lizard') is a genus of very large therizinosaurid dinosaurs that lived during the Late Cretaceous period in what is now Asia. It contains a single species, Therizinosaurus cheloniformis, known from the fossiliferous Nemegt Formation. The first remains of Therizinosaurus were found in 1948 by a Mongolian field expedition in the Gobi Desert and later described by Evgeny Maleev in 1954. The genus is only known from a few bones, including gigantic manual unguals (claw bones), from which it gets its name, and additional findings comprising fore and hindlimb elemen

Segnosaurus is a genus of therizinosaurid dinosaur that lived in what is now southeastern Mongolia during the Late Cretaceous, about 102–86 million years ago. Multiple incomplete but well-preserved specimens were discovered in the Gobi Desert in the 1970s, and in 1979 the genus and species Segnosaurus galbinensis were named. The generic name Segnosaurus means "slow lizard" and the specific name galbinensis refers to the Galbin region. The known material of this dinosaur includes the lower jaw, neck and tail vertebrae, the pelvis, shoulder girdle, and limb bones. Parts of the specimens hav

Alxasaurus (; meaning "Alxa lizard") is a genus of therizinosauroid theropod dinosaurs from the Early Cretaceous (Albian age) Bayin-Gobi Formation of Inner Mongolia. It is known from five specimens, recovered from the Bayin-Gobi in 1988, as part of the China-Canada Dinosaur Project. During their preparation, palaeontologists Dong Zhiming and Dale Russell noted strong similarities to Segnosaurus. In 1993, they described Alxasaurus and named its type species, A. elesitaiensis. While therizinosaurs had previously been tentatively seen as late-surviving basal sauropodomorphs, the description of Al

Beipiaosaurus is a genus of therizinosauroid theropod dinosaurs that lived in China during the Early Cretaceous in the Yixian Formation. The first remains were found in 1996 and formally described in 1999. Before the discovery of Yutyrannus, Beipiaosaurus were among the heaviest dinosaurs known from direct evidence to be feathered. Beipiaosaurus is known from three reported specimens. Numerous impressions of feather structures were preserved that allowed researchers to determine the feathering color which turned out to be brownish.

Therizinosauridae (meaning 'scythe lizards') is an extinct family of derived (advanced) therizinosauroid dinosaurs whose fossil remains have been found in mostly Late Cretaceous boundary. Even though representative fossils have only been found throughout Asia and North America, the range of Therizinosauridae is believed to have spanned much of the supercontinent of Laurasia based on several footprints and isolated remains in Europe and Africa. As of 2025, the family Therizinosauridae comprises nine definitive genera.

Nothronychus (meaning "slothful claw") is a genus of therizinosaurid theropod dinosaurs that lived in North America during the Late Cretaceous period. The type species, Nothronychus mckinleyi, was described by James Kirkland and Douglas G. Wolfe in 2001. It was recovered near New Mexico's border with Arizona, in an area known as the Zuni Basin, from rocks assigned to the Moreno Hill Formation, dating to the Turonian stage of the Late Cretaceous. A second specimen, described in 2009 as a second species, Nothronychus graffami, was found in the Tropic Shale of Utah, dating to between one million

Erlikosaurus (meaning "Erlik's lizard") is a genus of therizinosaurid that lived in Asia during the Late Cretaceous period. The fossils, a skull and some post-cranial fragments, were found in the Bayan Shireh Formation of Mongolia in 1972, dating to around 96 and 89 million years ago. These remains were later described by Altangerel Perle and Rinchen Barsbold in 1980, naming the new genus and species Erlikosaurus andrewsi. It represents the second therizinosaur taxon from this formation (after Segnosaurus), with the most complete skull among members of this peculiar family of dinosaurs.

Therizinosaurs (; once called segnosaurs) are an extinct group of large herbivorous theropod dinosaurs whose fossils have been mainly discovered from Cretaceous deposits in Asia and North America. Potential fragmentary remains have also been found in Jurassic deposits of Asia and Europe. Various features of the forelimbs, skull and pelvis unite these finds as both theropods and maniraptorans, making them relatives of birds. The name of the representative genus, Therizinosaurus, is derived from the Greek (, 'to reap' or 'scythe') and (, 'lizard'). The older representative, Segnosaurus, is deriv

Nanshiungosaurus (meaning "Nanxiong's lizard") is a genus of therizinosaurid that lived in what is now Asia during the Late Cretaceous of South China. The type species, Nanshiungosaurus brevispinus, was first discovered in 1974 and described in 1979 by Dong Zhiming. It is represented by a single specimen preserving most of the cervical and dorsal vertebrae with the pelvis. A supposed and unlikely second species, "Nanshiungosaurus" bohlini, was found in 1992 and described in 1997. It is also represented by vertebrae but this species however, differs in geological age and lacks authentic charact

Falcarius (meaning "sickle cutter") is a genus of primitive therizinosaur dinosaur that lived during the Early Cretaceous period in what is now North America. Its remains were first collected in the Cedar Mountain Formation in 1999, with subsequent findings made during the 2000s. The genus is known from multiple specimens ranging from immature to fully-grown individuals.

Suzhousaurus (meaning "Suzhou lizard") is an extinct genus of large therizinosaurid dinosaurs from the Early Cretaceous of China. The genus is known from two specimens discovered in the Xiagou and Zhonggou Formations, both part of the Xinminbao Group. These findings were made during fieldwork in 1999 and 2004.

Enigmosaurus (meaning "enigma lizard" or "enigmatic lizard") is a genus of therizinosauroid that lived in Asia during the Late Cretaceous period. It was a medium-sized, ground-dwelling, bipedal herbivore that represents the third therizinosaur taxon from the Bayan Shireh Formation, although it is known from the lower part. The genus is monotypic, including only the type species E. mongoliensis, known from a well-preserved pelvis and other tentative body remains.

Erliansaurus (meaning "Erlian lizard") is a genus of therizinosaurian theropod dinosaur that lived in Asia during the Cenomanian stage of the Late Cretaceous period in what is now Nei Mongol, Iren Dabasu Formation.

Neimongosaurus (meaning "Nei Mongol lizard") is a genus of herbivorous therizinosaurian theropod dinosaur that lived in China during the Late Cretaceous period. Its fossils are known from the strata of the Iren Dabasu Formation. It is known from two specimens, discovered in 1999 by researchers from the Ministry of Land and Resources and described two years later. One species, N. yangi, is known, named after Chinese palaeontologist Yang Zhongjian.

Martharaptor is a genus of therizinosauroid theropod dinosaurs from the Early Cretaceous of the Cedar Mountain Formation in Utah. They can be distinguished from other therizinosauroids by means of several features of the skeleton (particularly the hands and feet) which were intermediate between early therizinosaurs such as Falcarius and Beipiaosaurus, and more "advanced" members of the group like therizinosaurids. The deep and homogeneous hand claws clearly differ from the case in early therizinosauroids, but the foot has not yet acquired the robust morphology of therizinosaurids.

Jianchangosaurus ("lizard from Jianchang County") is a genus of therizinosaurian dinosaur that lived approximately 126 million years ago during the early part of the Cretaceous Period from the Yixian Formation in what is now China. The type specimen, a juvenile, was discovered in Jianchang County, in the western part of Liaoning Province. It was described in 2013 by a team of palaeontologists from the Henan Museum, who determined that it was among the most basal therizinosaurs.

Duonychus (meaning "two claws") is an extinct genus of therizinosaurid theropod dinosaurs that lived during the Late Cretaceous (Cenomanian to early Coniacian age) of what is now Mongolia. It is known from a partial skeleton, including several vertebrae, most of the forelimbs, and part of the pelvic girdle, found in outcrops of the Bayanshiree Formation. The remains were discovered in 2012 by the Mongolian Academy of Sciences and briefly mentioned in later conference abstracts. The genus contains a single species, Duonychus tsogtbaatari, which was formally described in 2025.

Paralitherizinosaurus is an extinct genus of therizinosaurid theropod dinosaurs from the Late Cretaceous Osoushinai Formation of Hokkaido, Japan. The genus contains a single species, Paralitherizinosaurus japonicus, known from a partial right hand and cervical vertebra. Paralitherizinosaurus represents the youngest therizinosaur known from Japan.

Lingyuanosaurus is a genus of therizinosaurian theropod from the Early Cretaceous of Liaoning Province, China. The type and only species is L. sihedangensis. It was uncovered within one of the formations that make up the Jehol biota, although the exact geological formation — and therefore also its precise geological age — is unknown. ==Discovery== thumb|left|A map of the area of China where Lingyuanosaurus was found, with the town of Sihedang visible on the left (C) The holotype of Lingyuanosaurus, given the designation IVPP V 23589, was discovered at a fossil locality near a town called Sihed