New look at the lobster Eryma greppini, OPPEL, 1861 (Crustacea, Decapoda, Erymidae) from the Middle Jurassic of France and Switzerland

Erymid lobsters (Decapoda, Erymidae) are a relatively abundant family of decapod crustaceans with a presumed conservative morphology. For these reasons, numerous species of erymids have been synonymized with others by early efforts to review the family. Eryma greppini OPPEL, 1861, is one of these. A well-preserved specimen of erymid lobster assigned to this species has recently been traced in the palaeontological collections from the Universite Claude Bernard Lyon 1 (France). Study of this specimen and examination of the type material of Eryma greppini, Eryma affinis FERRY, 1865, and Eryma bedeltum (QUENSTEDT, 1857) lead us to consider Eryma greppini to be a valid species, characterized by a peculiar pair of dorsal domes. A lectotype is herein designated for Eryma greppini. This study is a first step toward the necessary revision of erymid lobsters and proves the importance of taxonomic studies based on type material.