Ichnology of the Late Paleozoic Paganzo and Calingasta-Uspallata Basins of Western Argentina

Several trace fossil assemblages have been recorded in the upper Paleozoic Paganzo and Calingasta-Uspallata basins of northwestern Argentina. In the Paganzo Basin, ichnofossil assemblages are widespread, being present in both the Lower and Upper sections of the Paganzo Group. The Mermia, depauperate Cruziana and depauperate Mermia Ichnofacies are common in the lower section. They occur in glacial-postglacial settings and in transgressive settings not connected directly with ice masses. In the Upper section, the Scoyenia Ichnofacies, as well as eolian-related trace fossil assemblages, occur in connection to more arid continental facies. The ichnological record of the Calingasta-Uspallata Basin is relatively scarce. In this basin, the depauperate Cruziana Ichnofacies has been documented in post-glacial deposits of the Hoyada Verde Formation, suggesting stressed conditions related to a wave-dominated prograding deltaic system. Archetypal and more diverse Cruziana Ichnofacies have not been recorded yet in these basins, contrary to the situation observed in other Gondwanic settings. The vertebrate trace fossil record of the late Paleozoic in Argentina is still poor.