Barsbold and Perle named the group Segnosauria as an infraorder of Theropoda in 1980.
Dong Zhiming went further, placing the segnosaurs in their own order, Segnosaurischia.
This name has been abandoned since the discovery that segnosaurs are a specialized group within the suborder Theropoda.
Clark et al.
2004 considered Segnosaurischia a synonym of Therizinosauroidea.

The superfamily Therizinosauroidea had been established by Maleev in 1954, to include only the bizarre, giant-clawed theropod Therizinosaurus.
When it was later realized that Therizinosaurus was an advanced segnosaur, Therizinosauroidea was given a phylogenetic definition to include both groups, and has largely replaced the use of the older name Segnosauria in phylogenetic studies, mainly because of the association of the name Segnosauria with the discredited idea that these animals were relatives of prosauropods.

The following taxonomy follows Zanno, 2010 unless otherwise noted.

Branch Therizinosauria
Genus Eshanosaurus?

Genus Falcarius
Genus Martharaptor
Genus Jianchangosaurus (Pu et al.,
2013)
Superfamily Therizinosauroidea
Genus Beipiaosaurus
Genus Enigmosaurus
Genus Erliansaurus
Genus Neimongosaurus
Genus Suzhousaurus
Family Alxasauridae
Family Therizinosauridae
Barsbold and Perle named the group Segnosauria as an infraorder of Theropoda in 1980. Dong Zhiming went further, placing the segnosaurs in their own order, Segnosaurischia. This name has been abandoned since the discovery that segnosaurs are a specialized group within the suborder Theropoda. Clark et al. 2004 considered Segnosaurischia a synonym of Therizinosauroidea.
The superfamily Therizinosauroidea had been established by Maleev in 1954, to include only the bizarre, giant-clawed theropod Therizinosaurus. When it was later realized that Therizinosaurus was an advanced segnosaur, Therizinosauroidea was given a phylogenetic definition to include both groups, and has largely replaced the use of the older name Segnosauria in phylogenetic studies, mainly because of the association of the name Segnosauria with the discredited idea that these animals were relatives of prosauropods.
The following taxonomy follows Zanno, 2010 unless otherwise noted.
Branch Therizinosauria
Genus Eshanosaurus?
Genus Falcarius
Genus Martharaptor
Genus Jianchangosaurus (Pu et al., 2013)
Superfamily Therizinosauroidea
Genus Beipiaosaurus
Genus Enigmosaurus
Genus Erliansaurus
Genus Neimongosaurus
Genus Suzhousaurus
Family Alxasauridae
Family Therizinosauridae
Therizinosauria