The occurrence of Phacopida trilobites from Pimenteira Formation at João Costa, Piauí, Brazil

Abstract

The marine macroinvertebrate fossils from the Devonian of the Parnaíba Basin are among the most diverse of Paleozoic of Brazil. In recent years, most revisions on these fossils involved trilobites from the Pimenteira and Cabeças formations, in the region of Picos and Pimenteiras cities, in the Piauí State. This survey reports the occurrence of Devonian trilobites from the Pimenteira Formation cropping out at João Costa city, in the region of Serra da Capivara National Park, southeastern Piauí State, where two species were recognized: Burmeisteria notica Clarke, 1913 and Metacryphaeus cf. australis Clarke, 1913. The wide occurrence of these genera in the Malvinokaffric Realm shows that transgressive events during part of the Devonian favored the faunal communication between the Andean, Brazilian and South African provinces through the reduction of geographical barriers. Finally, although the still preliminary character of the studies on Pimenteira Formation trilobites, this unit is already providing new paleontological data that contribute to the understanding of these fossil assemblages.