“…Previous studies have demonstrated that a large proportion of the cranial cavity of turtles is occupied by subdural and epidural space (Evers et al, 2019;Ferreira et al, 2022;Lautenschlager et al, 2018). Thus, turtle endocasts are relatively poor predictors of brain morphology (Edinger, 1929;Evers et al, 2019;Ferreira et al, 2022;Mautner et al, 2017;Paulina-Carabajal et al, 2013;Wyneken, 2001;Zangerl, 1960). This pattern also holds in certain other vertebrate taxa in which the brain volume does not fill most of the endocranial space, such as squamates (Allemand et al, 2023) and cetaceans (Boessenecker et al, 2017;Ichishima, Kawabe, & Sawamura, 2021;Racicot, 2022), but differs from the relatively good reflection of brain shape by endocast shape in archosaurs (Iwaniuk & Nelson, 2002;Watanabe et al, 2019), many mammals (e.g., De Miguel & Henneberg, 1998Haight & Nelson, 1987;Jerison, 1973;Macrini et al, 2007), and amphibians (Clement et al, 2021).…”