We describe a very diverse and rich assemblage of fossil fishes from the Upper Pennsylvanian (Missourian) interval of the Horquilla Formation in the Robledo Mountains of southern New Mexico, USA. The assemblage includes bransonelliforms, symmoriiforms, a ctenacanthiform, a jalodontid, euselachians, neoselachians, an orodontiform, a helodontiform, an eugeneodontiform, a petalodontiform, a psephodontid, an acanthodian and actinopterygians. For the first time, the vascularization system of the teeth of Adamantina, Bransonella, Helodus and Agassizodus has been studied using a micro-CT. Besides the diverse fish assemblage from the Robledo Mountains, some other new records of Paleozoic chondrichthyans in New Mexico are documented.