A striking convergence in conchological morphology between Oligocene-Miocene lottiids (Mollusca, Patellogastropoda) from the North Sea Basin and the Paratethys

The protoconch and teleoconch morphology of Patella compressiuscala Karsten, 1849 (North Sea Basin, Chattian – Langhian) is described and illustrated. The new genus Boreoblinia is established for this species which is characterized by a protoconch indicative of a lecithotrophic type of early development, lacking even a short free-swimming larval stage. The distinctness of Boreoblinia gen. nov. from other Patellogastropoda such as Tectura, Patella, and Helcion exhibiting the typical patellogastropod protoconch types is supported also by its unusual shell structure. An amazing heterochronous convergence of both protoconch and teleoconch morphology between the new species from the North Sea Basin and Miocene Flexitectura subcostata (Sinzow, 1892) from the Sarmatian of the Paratethys is shown. Detailed descriptions and SEM images of species involved are presented.