Segnosaurus means "Slow reptile". Its feet and lower jaw are similar to that of Erlikosaurus. Therizinosauria used to be called "segnosauria" and it had only three members in it, Segnosaurus, Erlikosaurus, and Enigmosaurus (whose pelvis may very well belong to Erlikosaurus and viceversa). They used to be pictured as probable Sauropodomorphs whose hips evolved in convergence to Dromaeosauria and so on. Big mixups back then. Big mixups. Now they know better.