The holotype of Judithemys sukhanovi gen et. sp. nov. from the Late Cretaceous (Campanian) Dinosaur Park Formation of Alberta, Canada, has been included in four cladistic analyses. New material allows for a more complete description of this taxon. Judithemys sukhanovi is represented by 65 specimens (most very fragmentary) including one virtually complete skeleton (the holotype) and several partial shells. It differs from all other “macrobaenids” in the combination of wide vertebral scales, absence of central plastral fontanelles, and lack of strongly upturned peripherals. The morphology of Judithemys reiterates a suite of characters (large size, well-differentiated neurals reduced to eight, and greater overlap of the twelfth marginal scales onto the second suprapygal) common to Late Cretaceous–Paleocene “macrobaenids” and distinct from Early Cretaceous members. Judithemys and “Clemmys” backmani are close in morphology, geography, and stratigraphic position and are possibly closely related phylogenetically. A preliminary phylogenetic analysis supports the hypothesis that Judithemys is not part of the crown group.