Taxonomy of Devonian conulariids (Cnidaria) from Mato Grosso do Sul, Paraná Basin, Brazil

Abstract

Devonian conulariids (Cnidaria) from the Ponta Grossa Formation, Paraná Basin, have been studied since 1913, when the fauna composed of Paraconularia africana (Sharpe), Conularia quichua Ulric h, and Paraconularia ulrichana (Cla rke) was first described. Since then, much work has been done encompassing their taphonomy, systematics, and paleobiology. However, until now the studies have relied on conulariids from the eastern border area of the basin. Therefore, there was a lack of information on the conulariids of the northwestern border area of the Paraná Basin, particularly from the Mato Grosso do Sul, for which there are no previous descriptions of these fossils. The present analysis of specimens from the Ponta Grossa Formation in Mato Grosso do Sul revealed the presence of Conularia quichua, Paraconularia africana, P. ulrichana, and Reticulaconularia caetensis sp. nov. Therefore, the diversity of the conulariid fauna recorded from the northwest border area of the basin is greater than that of the eastern border area, where the genus Reticulaconularia has not yet been found, and the presence of Paraconularia ulrichana still needs confirmation. Furthermore, our data suggest that the Paraná Basin had narrow connections with the Devonian seas of Bolivia, at least during sea-level rise, as indicated by the shared benthic marine fauna. Keywords: Conulariids, Lower Devonian, Ponta Grossa Formation, Paraná Basin.