The cladogram below follows the 2019 phylogenetic analysis by Scott Hartman and colleagues, which is largely based on the work from Zanno in 2010. While most therizinosaurids are recovered in relatively traditional, well-established positions, the therizinosauroid "N." bohlini was unusually recovered as a therizinosaurid taxon: Paleobiology Feeding In 2009, Zanno and colleagues stated therizinosaurs were the most-widely regarded candidates for herbivory among theropods based on the small, densely packed, coarse serrations; lance-shaped teeth with a relatively low replacement rate; a well-developed keratinous beak; long neck for browsing; relatively small skulls; a very large gut capacity as indicated by the rib circumference at the trunk and the outwards flaring processes of the ilia; and the notable lack of cursorial adaptations in the hind limbs. All of these features suggest that members of this family feed on vegetation, as well as pre-processing it within their mouths to begin the breakdown of cellulose and lignin. This is perhaps even more so true for therizinosaurids, which seem to have further exploited these characters. One of the most notable adaptations in advanced therizinosaurids are the four-toed feet, which had a fully functional, weight-bearing first digit that was likely adapted to slow life-style. Zanno and colleagues found that Ornithomimosauria, Therizinosauria, and Oviraptorosauria had either direct or morphological evidence for herbivory, which would mean either this diet evolved independently multiple times in coelurosaurian theropods or that the primitive condition of the group was at least facultative herbivory with carnivory only emerging in more derived maniraptorans. The skull of therizinosaurids was specialized as well, as it was likely capped off with a beak-like rostrum in the front. It has been argued that this rostrum was likely covered with a keratinous beak, an adaption that might have helped to enhance cranial stability by mitigating the stress and strain experienced by the skull during feeding. As indicated by their respective dental morphologies, the contemporaneous therizinosaurids Erlikosaurus and Segnosaurus were separated by niche partitioning. These differentiations include the relatively indistinct and symmetrical teeth with moderate serrations (denticles) in Erlikosaurus, and the enlarged serrations in Segnosaurus composed of additional carinae and folded carinae with denticulated front edges, which together created a roughened, shredding surface near the base of the tooth crowns that was apparently unique to Segnosaurus and suggest they consumed unique food resources or used highly specialized feeding strategies, and had a higher degree of oral food processing than other therizinosaurids.