Common but unseen: anatomical redescription of Tectura virginea (Müller, 1776) (Patellogastropoda: Lottioidea: Tecturidae)

Tectura virginea (Müller, 1776) is a small limpet distinguished by a white shell adorned with pink radial rays. It inhabits low intertidal to subtidal zones along the shores of the North Atlantic and Mediterranean. Although it is relatively common, comprehensive anatomical studies have been limited. This study employs 3D visualization techniques, combining histology and micro-CT, to redescribe the internal anatomy of T. virginea. Our findings reveal new morphological details, particularly the anatomy of buccal structures, such as odontophore muscles and cartilages, and subradular organ, that likely represent adaptations for feeding on coralline algae. Previous phylogenetic analyses placed T. virginea as a sister taxon to all other members of Lottioidea. Tectura virginea has anatomical features that also separate it from other Lottioidea: three pair of odontophore cartilages, where the anterior cartilages are fused, a dorsal approximator muscle that connect the cartilages, lamellated licker projections on the subradular organ, and a pigmented sensory streak associated with the osphradium. The mantle of T. virginea possesses distinctive "repugnatorial"glands, a feature rare among patellogastropod limpets, although the structure and function of these glands remain unclear. Tectura virginea is the type species of its genus, and based on phylogenetic evidence and these diagnostic anatomical features, we reinstate Tecturidae Gray, 1847 at family level. This study underscores the importance of detailed anatomical research in understanding the evolutionary history and adaptive strategies of limpets, which are overlooked even in common coastal species.