Andean Geology 39 (1): 180-200. January, 2012 Andean Geology formerly Revista Geológica de Chile www.andeangeology.cl A Late Eocene age proposal for the Loreto Formation (Brunswick Peninsula, southernmost Chile), based on fossil cartilaginous fishes, paleobotany and radiometric evidence Rodrigo A. Otero1, Teresa Torres2, Jacobus P. Le Roux3, Francisco Hervé4, C. Mark Fanning5, Roberto E. Yury-Yáñez6, David Rubilar-Rogers7 1 Consejo de Monumentos Nacionales, Av. Vicuña Mackenna 084, Providencia, Santiago, Chile.
[email protected] 2 Facultad de Ciencias Agronómicas, Universidad de Chile, Av. Santa Rosa 11315, Santiago, Chile.
[email protected] 3 Departamento de Geología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Plaza Ercilla 803, Santiago, Chile.
[email protected] 4 Escuela de Ciencias de la Tierra, Facultad de Ingeniería, Universidad Nacional Andrés Bello, Sazie 2350, Santiago, Chile.
[email protected] 5 Research School of Earth Sciences, Australian National University, Canberra, Australia.
[email protected] 6 Laboratorio de Zoología de Vertebrados, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile.
[email protected] 7 Área Paleontología, Museo Nacional de Historia Natural, Casilla 787, Santiago, Chile.
[email protected] ABStract. We present new data on the paleoichthyology, paleobotany and radiometric results of the Loreto Formation in the Brunswick Peninsula of southernmost Chile, that allow us to propose a Late Eocene age. The rich diversity of fossil cartilaginous fishes (Chondrichthyes, Elasmobranchii) recognized in upper levels of this unit includes the taxa Carcharias aff. ‘hopei’ (Agassiz), Odontaspis sp., Carcharoides catticus (Philippi), Striatolamia macrota (Agassiz), Anomotodon sp., Macrorhizodus praecursor (Leriche), Galeorhinus sp., Abdounia sp., Hexanchus sp., Squatina sp., Hexanchidae indet., Myliobatis sp., Myliobatoidea indet., and Ischyodus dolloi Leriche.