Nouveaux poissons acanthodiens du Dévonien du Spitsberg

Two new acanthodian species are described from the Spitsbergen Old Red Sandstone. Mesacanthus grandis n.sp. is represented by an articulated specimen showing unornamented body scales, elongate modified tectal scales, and a mesacanthid type of scapula. The second species, Xylacanthus minutus n.sp. is represented by a right branch of the mandible in lingual view, showing a single row of triangular striated teeth with an anterior flange. Phylogenetic affinities of these forms are discussed as well as their paleoenvironmental significance.