Challaia

Challaia is an extinct genus of prehistoric freshwater ray-finned fish that lived during the Triassic period in what is now Argentina. Two species are known, C. magna, most likely from the Cerro de Las Cabras Formation, and C. elongata from the Los Rastros Formation. Three other species, C. multidentata, C. striata and C.? cacheutensis, are considered nomina dubia.
C. elongata is the youngest known member of the Acrolepididae, a family of early ray-finned fishes that was dominant throughout the late Paleozoic, and survived into the Triassic.