Artículo leído en la Reunión 113 del Palaeontological Society of Japan, en Osaka, 15 de junio de 1974. | El reconocimiento paleontológico de los Andes en Perú y Bolivia fue realizado por los miembros de la Expedición Paleontológica a los Andes de la Universidad de Chiba en cooperación con el personal de los Servicios Geológicos de Perú y Bolivia de septiembre a diciembre de 1973.

In 1973 and 1979, the geological and palaeontological reconnaissance surveys on the Mesozoic group of Los Andes Cordillera, Central Peru were carried out by the members of Palaeontological Party of Chiba University and of Instituto de Geologico, Minero y Metalurgico, Ministerio de Energia y Minas, INGEMMET, as the cooperative study supported by the Overseas Scientific Research Funds, Ministry of Education, Government of Japan. The Jurasso•Triassic marine sediments are distributed widely on the western foot and the midst of Los Andes Cordillera in the southern part of Peru. Some Jurassic trigoniids from this part are described in this paper as one of the results obtained by the cooperative study. The fossils treated in this paper were collected by the geologists of INGEMMET through the geological survey for making the geological sheet map of the southern part of Peru. Their fossils are ...