The record of ostracod genus Harpabollia Schallreuter in upper Ordovician levels of the Paraná Basin, Brazil: its paleobiogeographic implications.

SALAS, MARIA JOSE; REILY, LIVIO; ADÔRNO, RODRIGO RODRIGUES; DO CARMO, DERMEVAL APARECIDO

Puerto Madryn

Jornada; Reunión Anual de Comunicaciones de la Asociación Paleontológica Argentina; 2018

Asociación Paleontológica Argentina

The knowledge of Paleozoic ostracods from Brazil is scarce and patchy, consisting only of isolated mentions. The first Ordovician ostracods, Satiellina paranaensis Adorno and Salas, 2016 and Conchoprimitia brasiliensis Adorno and Salas, 2016, were recently recorded in the Parana Basin. Currently, new material allowed the identification of Harpabollia n. sp. The species come from the lower levels of the Vila Maria Formation (Upper Ordovician-Silurian), composed of black shales at its base and sandstone to the top. The mudstone interval was interpreted as a periglacial marine environment from mid to outer continental shelf. The unit with its underlay Iapó Formation would register the Hirnantian glaciation, periglacial environment and its subsequent recovery, showing a correlation between the Brazilian and North African basins, as much by the fauna as by the similarity in the stratigraphic sequences. The presence of Harpabollia and Satiellina support the connection between these basins together with the peri-Gondwanic platforms (Iberia, Armorica, Carnic Alps) and Bohemia. The first record of Harpabollia occurs in Sandbian levels of the Precordillera Argentina migrating to North Gondwana and Peri-Gondwana during the Late Ordovician. Harpabollia harparum association, well studied and known in Carnic Alps, Bohemia and Baltoscandian Palaeobasin, is considered part of the Hirnantia fauna representing a cold-water assemblage. The presence of Harpabollia in the Parana basin would agree with the features of this association, however, a deeper analysis and the record of more material is necessary for a better knowledge of the studied fauna.