CONICET | Buscador de Institutos y Recursos Humanos

Abstract. A new reticulosan sponge was discovered in Floresta Formation (early late Tremadocian) Mojotoro range, Salta, Argentina. The specimen has semi-regular to irregular skeletal structure in a single layer, with stauracts of several sizes and some monaxons. Subparallel strands with rare irregularly distributed and small parietal gaps. The poor preservation, the absence of base and osculum, prevent their inclusion in a particular genus of reticulosans. The occurrence of the Argentinean reticulosan form represents a new evidence that some elements of the ?Reticulosan? sponges from the Cambrian fauna continues into the Lower Ordovician and survived well at different paleo-latitudes and environments.