First vertebrate body remains from the Permian of Argentina (Elasmobranchii and Actinopterygii)

Abstract

Isolated shark and actinopterygian teeth and scales were found in marine levels of the El Jarillal Formation (Early Permian), which crops out near the Cerro Vizcacha, Provincia de Mendoza, Argentina. Scarce previous Paleozoic vertebrate remains are known from Argentina and none was described from the Permian. Only tetrapod traces were reported before. However, vertebrates (especially fishes) are relatively abundant in other South American countries such as Brazil, Bolivia, Uruguay, Colombia, and Venezuela, from where “agnathan”, placoderm, acanthodian, chondrichthyan, actinopterygian, dipnoan, crossopterygian, and tetrapod remains are known. In this paper we report the southernmost Paleozoic vertebrates body remains record and the first description of a hybodontid tooth from the Paleozoic of South America. Hybodontiforms were previously known in South America by fin spines, placoid scales and one putative undescribed tooth. We also give the first report South American shark dermal denticles traditionally ascribed to the form genus Petrodus, which probably belongs to a hybodontoid shark. Finally, several “basal actinopterygians” scales and teeth are assigned to morphotypes found in other South American Permian Formations. We did not found other fish taxa already known from late Paleozoic beds of the continent such as xenacanthiform sharks, lungfishes or coelacanthiforms. As an appendix, we summarize the Permian fish record of the continent.