Early Jurassic Bivalvia of Argentina. Part 1: stratigraphical introduction and superfamilies Nuculanacea, Arcacea, Mytilacea and Pinnacea. Palaeontographica Abteilung A Palaeozoologie-Stratigraphie, 199(1-3) 1987: 23-111. 65 [Zoological Record Volume 124]