run along the skull instead of across it. An unpublished study conducted by Vernon Meidlinger-Chin in 2013 suggested that previous studies lacked focus on endocranial details. The study found that the Cryolophosaurus fossil has a nearly complete, undistorted cranial cavity which is complete enough to give an approximate shape and size of the living brain. The endocast features clarified the dissimilarity of the skull with those of Allosauroids and Coelurosaurs giving Cryolophosaurus a basal position in Theropoda. Closer examination of how the skull bones fused reviewed details in the snout and forehead that are exceptionally similar to Dilophosaurus. Classification Classification of Cryolophosaurus is difficult because it has a mix of primitive and advanced characteristics. The femur has traits of early theropods, while the skull resembles much later species of the clade Tetanurae, like China's Sinraptor and Yangchuanosaurus. This led Paul Sereno et al. (1994) to place Cryolophosaurus in the taxon Allosauridae. Originally, Hammer and colleagues suspected that Cryolophosaurus might be a ceratosaur or even an early abelisaur, with some traits convergent with those of more advanced tetanurans, but ultimately concluded that it was itself the earliest known member of the tetanuran group. While a subsequent study by Hammer (along with Smith and Currie) again recovered Cryolophosaurus as a tetanuran, a later (2007) study by the same authors found that it was more closely related to Dilophosaurus and Dracovenator. Sterling Nesbitt et al. (2009), using the characters of Tawa found Cryolophosaurus to be neither a dilophosaurid nor averostran neotheropod but instead the sister group of a clade composed of dilophosaurids and averostrans. However, in 2012, Matthew Carrano found that Cryolophosaurus was a tetanuran, related to Sinosaurus, but unrelated to Dilophosaurus. In 2020, a monograph of Dilophosaurus found Cryolophosaurus to be a derived neotheropod, close to Averostra, in a more derived position than Zupaysaurus, but less than Dilophosaurus. The following cladogram illustrates a synthesis of the relationships of the early theropod groups compiled by Hendrickx et al. in 2015. However, a 2020, a study conducted Adam Marsh and Timothy Rowe found Cryolophosaurus to be a basal Neotheropod. While it was still closer to Averostra than Coelophysoidea was, it was still more basal than Dilophosaurus. Paleobiology Cranial ornamentation Cranial display features, such as the one possessed by Cryolophosaurus, make sense in social, gregarious animals, where other members of the species are available to observe and interpret messages of sexual status. Kevin Padian et