A new Late Carboniferous aeduellid genus (Actinopterygii: Aeduelliformes) from Saint-Étienne basin (France) and the phylogeny and palaeobiogeography of variscan actinopterygians

Abstract We erect here the new aeduellid Stephaniella melanocephala gen. et sp. nov. from the Late Carboniferous of the Saint-Étienne Basin (Loire, France). This is the first vertebrate to be described in detail from this basin. It is characterized by a unique combination of features such as four extrascapulars, a low maxilla, a trapezoidal suboperculum, two branchiostegal rays, and a sharp caudal inversion. It exhibits a unique large antero-dorsal process of the suboperculum that sets it apart from all other aeduellids. We also redescribe the aeduellid Puertollanichthys ritchiei from the Late Carboniferous of the Puertollano Basin (Spain). This work allows a better reconstruction of the phylogeny of Aeduellidae and confirms several assumptions made in recent studies. Our phylogenetic analysis finds Stephaniella melanocephala Gonçalves et al. gen. et sp. nov. as a basal member within Aeduellidae in a clade comprising P. ritchiei and Spinarichthys dispersus. This helps to decipher the early evolutionary history of this family. We highlight that aeduellids underwent an initial radiation in the Stephanian B–C, quickly followed by dispersal events in the northern foreland, hinterland, and southern foreland of the Variscan Belt. Dispersions continued during the Autunian in the Saar-Nahe Basin (Germany, northern foreland).