Asterozoans from the Devonian of the Paraná Basin, South Brazil

For a long time, as the asterozoan studies were rare among Devonian invertebrates of the Paraná Basin, the knowledge about the taxonomy, taphonomy, and palaeoecology of this regional group remained extremely limited. Therefore, this research focuses for the first time on the detailed identification and classification of fossil asteroids and ophiuroids from the Jaguariaíva and São Domingos members of the Ponta Grossa Formation. As a result, four species are described herein, Paranaster crucis nov. gen., nov. sp., Magnasterella darwini (Clarke, 1913) nov. gen., Encrinaster pontis (Clarke, 1913), and Marginixnotatus nov. sp. In addition, the Paranasteridae nov. fam. is also proposed. On the other hand, the taphonomic analysis of this asterozoans, together with the interpretation of sedimentary matrix and associated fossil assemblages, reveals important palaeoenvironment details from the Devonian of the Paraná Basin. These echinoderms lived in a marine platform governed by a polar climate and low sedimentation rates. But the commonly articulated asterozoans also support important events of rapid burial. Finally, this research expands the diversity of malvinokaffric echinoderms, contributing to the palaeoecological reconstruction of the Ponta Grossa Formation.