A new actinopterygian Cheirolepis jonesi nov. sp. from the Givetian of Spitsbergen, Svalbard

Abstract

© Copyright the authors. This work is licensed under a Creative Commons Attribution 4.0 International License. Two specimens of a new early actinopterygian Cheirolepis jonesi nov. gen. et sp. have been collected from the lagoonal Middle Devonian (Givetian) Fiskekløfta Member, the upper member of the Tordalen Formation in the Mimerdalen Subgroup of Spitsbergen. This is the second oldest Cheirolepis species known from articulated remains. The holotype consists of an articulated head and the anterior trunk. The other specimen is an articulated skull which was 3D scanned to determine the internal structure and general architecture. The new taxon differs from other Cheirolepis species in the relative dimensions of the bones of the head, including a narrow anterior end of the dentary, longer accessory operculum and correspondingly shorter dermohyal, as well as a longer premaxilla and proportionally larger quadratojugal, and the organisation and relative size of the teeth.