 "Eocasea" is the oldest and most basal member of Caseidae, lacking many of the specialized anatomical features that characterize later members of the group.Caseids are notable for being one of the first groups of tetrapods to evolve herbivory; large-bodied taxa such as "Casea" and "Cotylorhynchus" have barrel-shaped rib cages and leaf-shaped, serrated teeth that are clear adaptations for breaking down plant cellulose.