shows the placement of Therizinosaurus within Therizinosauria according to Hartman and colleagues in 2019: Paleobiology Feeding In 1993 Dale A. Russell and Donald E. Russell analyzed Therizinosaurus and Chalicotherium, and noted similarities in their respective body plan, even though they form part of different groups. Both genera had large, well-developed, and relatively strong arms; the pelvic girdle was robust and suited for a sitting behavior; and the hindlimb (particularly the foot) structure was robust and shortened. They considered these adaptations to represent an example of convergent evolution—a condition where organisms evolve similar traits without necessarily being related—between extinct mammal and dinosaur genera. Moreover, the body plan is somewhat exhibited by the modern-day gorillas. Because the animals with this type of body plan are known to represent herbivores, the authors suggested this lifestyle for Therizinosaurus. Russell and Russell reconstructed the feeding behavior of Therizinosaurus as being able to sit while consuming foliage from large shrubs and trees. The plant material would have been harvested with its hands and this action was likely favored by its elongated neck which prevented the use of large amounts of force and effort. As its arms were long enough to have touched the ground during certain stances, they could have helped the dinosaur to rise from a prone position. If browsing in a bipedal stance, Therizinosaurus may have been able to reach even higher vegetation supported by its short and robust feet. Whereas Chalicotherium was more suited to hook branches, Therizinosaurus was better at pushing large clumps of foliage because of its long claws. It is also possible that Therizinosaurus was less capable of great precision in its movements than was Chalicotherium, due to the latter having more developed brain, dental and muscular capacities. Anthony R. Fiorillo and colleagues in 2018 suggested that Therizinosaurus had a reduced bite force that may have been useful for cropping vegetation or foraging, based on relative therizinosaurids such as Erlikosaurus and Segnosaurus. As the bite force started to decrease from primitive to derived therizinosaurians, Therizinosaurus, being a derived member, would have been subject to the evolutionary relationship. Arms and claws function When the genus was first described by Maleev in 1954, he considered that the unusually large claws were used to harvest seaweed. This was however, based on the assumption of a giant marine turtle. In 1970, Rozhdestvensky re-examined the claws and suggested a possible function specialized in opening termite