Morphological evolution of the neomorph in Choristodera. Red branches are taxa in which the neomorph is identified. Line drawings are the left supratemporal fenestra of choristoderes in dorsal view, the neomorph highlighted in red: a. Coeruleodraco jurassicus (PKUP V2003); b. Philydrosaurus proseilus (PKUP V2001); c. Ikechosaurus sunailinae (IVPP V9611-3), adapted from Brinkman and Dong (1993); d. Simoedosaurus dakotensis, adapted from Erickson (1987); e. Simoedosaurus lemoinei, adapted from Russell-Sigogneau and Russell (1978), the neomorph is in medial view; f. Champsosaurus lindoei (CMN 8920), adapted from Dudgeon et al. (2020); g. Tchoiria klauseni (IGM 1/8), adapted from Ksepka et al. (2005); the line drawing is mirrored from the right supratemporal fenestra for comparisons with other species; h. Cladogram of Choristodera, composited from Dong et al. (2020) and Yuan et al. (2021). Line drawings not to scale. Abbreviations: p, parietal; pr, prootic; pt, pterygoid; q, quadrate; sq, squamosal.