Segnosaurus, meaning “slow lizard,” is a genus of therizinosaurid theropod dinosaur from the Cenomanian to Turonian stages of the Late Cretaceous Period. The type species, S. galinensis, was described in 1979 by Dr. A. Perle. It is known from three specimens consisting of a mandible, pelvis, hind limb, partial forelimb and vertebrae, as well as other fragments. The specimens were recovered from the Bayan Shireh Formation of the Mongolian People’s Republic.
Segnosaurus can be distinguished from other therizinosaurs by its midline jaw teeth that are peg-like and only slightly recurved and by the moderate compression of the pedal hooves. Based on the dentary cavity of the Segnosaurus, there is indication that it did not have as extensive cheeks as its close relative Erlikosaurus had.
Segnosaurus was featured in Robert Bakker’s novel “˜Raptor Red,’ portrayed as a burrower.