Overview of the Late Triassic (carnian) Actinopterygian Fauna from the Argana Basin (Morocco)

The continental outcrops of the Argana Basin (High Atlas of Morocco) have provided the richest tetrapod assemblage and the only known actinopterygian fauna of the Triassic of North Africa. Unlike the tetrapod remains, widely distributed throughout the basin, the actinopterygians are rare and come from a single locality. They are dated as the Late Triassic (Carnian) and have been attributed to six forms. Here, this ichthyofauna is reviewed for the first time since its original description. Two forms, endemic to the basin, are recognized as valid species and their generic attributions confirmed: the redfieldiiform Mauritanichthys rugosus, related to the genus Lasalichthys from the Late Triassic of North America, and the “perleidiform” Dipteronotus gibbosus, congeneric with Middle Triassic species of Europe. The other actinopterygian taxa are known by insufficiently preserved remains and need a complete material to be confidently identified. Two specimens previously referred to the redfieldiiform Ischnolepis are considered as Redfieldiiformes indet. and probably correspond to a new taxon. The three last forms, previously referred to the “perleidiforms” Procheirichthys and Perleidus, and to the redfieldiiform Atopocephala, are considered as Actinopterygii indet.