Saurischia Theropoda Tetanurae Coelurosauria Therizinosauroidea [?]
The therizinosauroidae were not recognizend as a distinct theropod taxon until 57 years after the first discovery in 1923, their true nature remained obscure until 1993 (Russell and Dong). Therizinosauroids are separated from other theropods for characters as small bulbous teeth with deticles aligned parallel to the longitudinal axis of each tooth, highly pneumatic cervical vertebrae, widely spaced cervical zygopophyses, tall neural arches in the anterior dorsal vertebrae, verry broad hips, opisthopubic pelvis, which is strongly deflected outwards in Segnosaurus and Nanshiungosaurus, short postacetabular region of the ilium, relatively short metatarsus, less than a third the length of the tibia and a functionally quadridactylous foot in which the proximal end of the first metatarsal reaches the tarsus. Two families are recognized by Russell and Dong (1993). Alxasauridae encompasses the more primitive generally smaller therizinosauroids of the Lower Cretaceous, whereas therizinosauridae are more derived, Upper Cretaceous forms.
A typical theropods in that the skulls where small, weakly armed with teeth and carried at the end of a long, lightly constructed neck.
Jurassic Early
China
Eshanosaurus deguchiianus - Dull Purplish Beds, Lower Lufeng Formation
Jurassic Middle
Jurassic Late
Cretaceous Early
US
Falcarius utahensis - Cedar Mountain Formation, Utah
The therizinosauroidae were not recognizend as a distinct theropod taxon until 57 years after the first discovery in 1923, their true nature remained obscure until 1993 (Russell and Dong). Therizinosauroids are separated from other theropods for characters as small bulbous teeth with deticles aligned parallel to the longitudinal axis of each tooth, highly pneumatic cervical vertebrae, widely spaced cervical zygopophyses, tall neural arches in the anterior dorsal vertebrae, verry broad hips, opisthopubic pelvis, which is strongly deflected outwards in Segnosaurus and Nanshiungosaurus, short postacetabular region of the ilium, relatively short metatarsus, less than a third the length of the tibia and a functionally quadridactylous foot in which the proximal end of the first metatarsal reaches the tarsus. Two families are recognized by Russell and Dong (1993). Alxasauridae encompasses the more primitive generally smaller therizinosauroids of the Lower Cretaceous, whereas therizinosauridae are more derived, Upper Cretaceous forms.
A typical theropods in that the skulls where small, weakly armed with teeth and carried at the end of a long, lightly constructed neck.
Jurassic Early
China
Eshanosaurus deguchiianus - Dull Purplish Beds, Lower Lufeng Formation
Jurassic Middle
Jurassic Late
Cretaceous Early
US
Falcarius utahensis - Cedar Mountain Formation, Utah
Martharaptor greenriverensis - Cedar Mountain Formation, Utah
China
Alxasaurus elesitaiensis - Bayin Gobi Formation
Beipiaosaurus inexpectus - Yixian Formation, Liaoning
Nanshiungosaurus
Nanshiungosaurus bohlini - Xinminbao Group
Suzhousaurus megatherioides - Xinminpu Group (= “Xinminbao”) Group
Cretaceous Late
US
Nothronychus mckinleyi - Moreno Hill Formation, New Mexico
Nothronychus graffami - Utah
China
Chilantaisaurus zheziangensis - Tangshang Formation
Erliansaurus bellamanus - Iren Dabasu Formation
Nanshiungosaurus
Nanshiungosaurus brevispinus - Nanxiong Formation
Neimongosaurus yangi - Iren Dabasu Formation
Segnosaurus galbinensis - Iren Dabasu Formation
Mongolia
Enigmosaurus mongoliensis - Baynshirenskaya Svita
Erlikosaurus andrewsi - Baynshirenskaya Svita
Therizinosaurus cheloniformis - Nemegt Formation, White Beds of Khermeen Tsav, Baynshirenskaya Svita
Segnosaurus galbinensis - Baynshirenskaya Svita
China
Alxasaurus elesitaiensis - Bayin Gobi Formation
Beipiaosaurus inexpectus - Yixian Formation, Liaoning
Nanshiungosaurus
Nanshiungosaurus bohlini - Xinminbao Group
Suzhousaurus megatherioides - Xinminpu Group (= “Xinminbao”) Group
Cretaceous Late
US
Nothronychus mckinleyi - Moreno Hill Formation, New Mexico
Nothronychus graffami - Utah
China
Chilantaisaurus zheziangensis - Tangshang Formation
Erliansaurus bellamanus - Iren Dabasu Formation
Nanshiungosaurus
Nanshiungosaurus brevispinus - Nanxiong Formation
Neimongosaurus yangi - Iren Dabasu Formation
Segnosaurus galbinensis - Iren Dabasu Formation
Mongolia
Enigmosaurus mongoliensis - Baynshirenskaya Svita
Erlikosaurus andrewsi - Baynshirenskaya Svita
Therizinosaurus cheloniformis - Nemegt Formation, White Beds of Khermeen Tsav, Baynshirenskaya Svita
Segnosaurus galbinensis - Baynshirenskaya Svita