ABSTRACT The mysterious scarcity of ‘fish’ in an extensive epicontinental sea has always intrigued countless researchers who worked with the South American Devonian, especially in the Malvinoxhosan (= Malvinokaffric) Paraná Basin. This scarcity is probably related to taphonomic factors and/or lack of experience of collectors with fossil ‘fish’. Currently, the vertebrate record of the Devonian of the Paraná Basin is restricted to three chondrichthyan fin fragments and an actinopterygian mandible. Here we describe the first ‘fish’ fossils from the northwest edge of the Paraná Basin, represented by Chondrichthyan fin spine, scales, and teeth, consisting in the oldest Devonian ‘fish’ in the basin, attributed to the Pragian-Emsian of Mato Grosso do Sul state. The morphology of the fin-spine is consistent with a stem chondrichthyan morphotype, and the teeth bear resemblance in cusp morphology to those of the protacrodontid type. Despite the low taxonomic refinement, this new record in the Devonian of the Paraná Basin shows the presence of ‘fish’ throughout the Basin already in the late Pragian – early Emsian. This is relevant, because the Paraná Basin is an important region for better understanding the distribution of the South American Devonian vertebrate fauna through time and space.