Published online by Cambridge University Press: 14 July 2015
Collections from the basal part of the marine Eocene Tejon Formation, Tehachapi Mountains, southern California, reveal new stratigraphic occurrences of patellogastropod limpets. Reports of these gastropods from California Paleogene strata are uncommon. The Tejon limpets are all members of the tropical genus Patelloida. Four taxa are represented in 33 specimens from five localities. These taxa include: mature specimens of P. tejonensis (Gabb, 1869), the first occurrence of the Eocene P. vokesi (Hickman, 1980) outside of Oregon, and P. triquetrus n. sp., described herein. Our study shows that a hypotype referred to P. tejonensis by Anderson and Hanna in 1925 is actually a fissurelloidean species, and we tentatively reallocate it to the genus Megathura Pilsbry, 1890. Analysis of depositional settings indicates that nearshore, shallow-subtidal depositional environments have higher patellogastropod abundance and diversity than intertidal or offshore-subtidal depositional environments. Morphological convergence between Tejon and Recent patellogastropod taxa is documented. Resemblance of the Eocene P. triquetrus n. sp. and an indeterminate Patelloidea sp. to the Quaternary “Collisella” scabra (Gould, 1846) and Lottia digitalis (Rathke, 1833), respectively, is remarkable.