Article: The relationship of the Mesozoic bivalve Atreta to the Dimyidae

Material recently collected from the Lower Lias (Lower Jurassic) of South Wales shows evidence of dimyarian musculature in Atreta intusstriata (Emmrich) proving that the previous assignment of Atreta to the monomyarian Plicatulidae Watson, 1930, by Cox (1964) is incorrect. The genus is therefore reassigned to the Dimyidae Fischer, 1886. A lectotype and paralectotypes are designated from material located in the Emmrich collection at the Geiseltal Museum, Halle, Germany.