coined to include Alxasaurus and Therizinosauridae, 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. Therizinosauroidea was first defined by Zhang et al. in 2001, as the clade containing all theropods more closely related to Therizinosaurus than to birds. This definition, however, defines the same group as the pre-existing Therizinosauria. An alternate definition was given by Clark in 2004 (as the last common ancestor of Therizinosaurus and Beipiaosaurus and all its descendants), comprising a narrower group that excludes more primitive therizinosaurs, such as Falcarius, and allows the name Therizinosauria to remain in use for the larger group comprising all therizinosaurs. This definition was followed by Sereno (2005), Zanno et al. (2009) and Zanno (2010), though other subsequent studies, such as Senter (2007, 2012) have continued to use Therizinosauroidea for the therizinosaur "total group". The cladogram below follows the extensive phylogenetic analysis of the Therizinosauria by Lindsay E. Zanno in 2010. Below is the recently performed phylogenetic analysis performed by Hartman et al. 2019 using the data provided by Zanno in 2010: Paleobiology Senses CT scans published by Stephan Lautenschlager et al. 2012 focused on the skull and brain cavity of Erlikosaurus, revealing it to have a large forebrain, and suggesting it had well developed senses of balance, hearing and smell, all of which would have been useful in evading predators, finding food, or in performing complex social behavior. These senses were also well-developed in earlier coelurosaurs and other theropods, indicating that therizinosaurs may have inherited many of these features from their carnivorous ancestors and used them for their specialized dietary purposes. Reproduction Dinosaur eggs with embryos of the Dendroolithidae type from the Nanchao Formation were identified as belonging to therizinosaurs based on anatomical features, and described by paleontologist Martin Kundrát and colleagues in 2007. The development of the embryos (their bones were extensively ossified) and the fact that no adults were found in association with the nests indicate that theirzinosaur hatchlings were precocial, capable of locomotion from birth, and able to leave their nests to feed alone, independently of their parents. The development of the teeth of the hatchlings was consistent with an omnivorous diet. Subterraneously constructed nests are also indicative of a lack of parental care during the incubation period. In a 2013 conference