Palaeontology and biostratigraphy of the Late Palaeozoic Copacabana Group at the Angosto del Beu, Bolivia

The Copacabana Group at the Angosto del Beu, northwestern Bolivia, yielded abundant invertebrates together with fusulinids and palynomorphs that sugge st an early Late Carboniferous-Early Permian age for the unit. The lower se ction of the group contains the fusulinid Millerella extensa Marshall, and is regarded as early Late Carboniferous in age. The upper section of the un it includes a palynological assemblage mainly dominated by taeniate disacca te pollen grains and monosaccates. The presence of Hamiapollenites insolitu s (Bharadwaj and Salujha) Balme, and Pakhapites fusus (Bose and Kar) Menend ez together with several biostratigraphically useful brachiopod species suc h as Kochiproductus peruvianus (d'Orbigny), Neospirifer condor (d'Orbigny), and Linoproductus cora (d'Orbigny), dates the upper section of the group a s Early Permian. Comparison with the lake Titikaka and the Altiplano outcro ps, and the Madre de Dies subsurface sections, provides a better picture of the palaeogeographical evolution of the Central Andes during the Late Pala eozoic.