A new aeduellid from the Permian Franchesse Lagerstätte (Bourbon-l’Archambault Basin, Allier, France) highlights the evolution of Palaeozoic actinopterygians

The new aeduellid Franchessella pohlcremeri gen. et sp. nov. from the Permian of France is described here in detail. It is based on well-preserved specimens including the holotype, three paratypes and 25 referred specimens (one preserved in a Discosauriscus coprolite revealed by synchrotron imaging), all originating from the early Permian of the Franchesse Lagerstätte, Bourbon-l’Archambault Basin (Allier). This new taxon is characterized by a unique combination of features such as a divided rostral; five posterior infraorbitals; a trapezoidal suboperculum; two branchiostegal rays with the ventral one being larger; straight lepidotrichia sutures; lepidotrichia ornamented with ridges; and concentric ridges on scales without serration on the posterior margin. The specimens described here represent different growth stages, from osteologically immature to mature individuals, allowing us to reveal the ontogeny of this new taxon. A phylogenetic analysis shows Franchessella pohlcremeri gen. et sp. nov. early-diverging within Aeduellidae, between Puertollanichthys from Spain and ‘Neslovicella’ elongata from Czech Republic and Germany. This phylogenetic position, together with the well-preserved Franchessella pohlcremeri gen. et sp. nov., provides new insights into the evolution of Carboniferous and Permian actinopterygians, particularly of their rostral and clavicular regions: the progressive disappearance of sensory canals in the rostral region of aeduellids and the acquisition of a large dorsal process in the clavicle combined with an ovoid cleithrum in Aeduelliformes. Finally, this new aeduellid adds to the faunal diversity of the Franchesse locality, which corresponded to a calm lakeshore deposit in the Variscan Belt during the Permian. https://zoobank.org/urn:lsid:zoobank.org:pub:C3FC99AF-7AEC-4D80-8EE0-3759AFCA276E