Conulariids from the Ponta Grossa Formation in the southwest of Gondwana, Mato Grosso do Sul State, Brazil

In the Mato Grosso do Sul State, there are outcrops of Paleozoic marine deposits of the Paraná Basin, which are characterized by the presence of a rich fauna of fossilized invertebrates (i.e., conulariids, Cnidarians), in the municipalities of Rio Negro, Rio Verde do Mato Grosso and Coxim. These fossils are from the Devonian (Pragian–Emsian) Ponta Grossa Formation and are very important for acquiring paleobiological and paleogeographical information on the Malvinokaffric Fauna. The conulariids analyzed were recorded in outcrops from the Rio Verde (P3), Fênix (P4) and Araras-Figueira (P6) mines. The conulariids belong to two species Paraconularia africana and Conularia quichua, with the latter predominating. Notably, the fossils are so well-preserved that the internal structures (e.g., axial pillar and carina) in the basal region of the theca are visible. According to literature data, rocks of the Ponta Grossa Formation from the Rio Negro and Coxim regions (e.g., outcrops MS14 Estância Nhecolândia and MS65 Corredeira do Caeté) also revealed the presence of Conularia quichua, Paraconularia africana, Paraconularia ulrichana and Reticulaconularia caetensis. These species have been broadly paleobiogeographic distributed in the Andeo-South African and Interior Gondwana seas bioregions. Keywords: taxonomy, conulariids, Devonian, Southwest Gondwana, paleobiogeography.