Hybodont sharks from the Middle Jurassic of the Inner Hebrides, Scotland

Non-marine Bathonian (Middle Jurassic) strata on the Isles of Eigg and Skye in Scotland have yielded fossil remains of eight hybodont shark taxa. Faunas from several horizons within the Lealt Shale and Valtos Formation on the Isle of Eigg include six species: Hybodus grossiconus, Hybodus sp. 1, Hybodus sp. 2, Lissodus leiodus, L. leiopleurus and Parvodus pattersoni. Large collections of teeth of L. leiodus and L. leiopleurus enable a better understanding of the dentitional patterns of the two species and their differential diagnosis. Surface-collecting from exposures of the Kilmalaug Formation on the Isle of Skye yielded hybodont teeth of two taxa: Hybodus sp. 3 and Acrodus caledonicus sp. nov. The occurrence of Acrodus in the Bathonian of Scotland is one of the youngest known occurrences of this genus, and the only non-marine record in the European Jurassic. Collectively, the hybodont assemblages from the Scottish Bathonian provide evidence that non-marine faunas of the group were specifically diverse in the Middle Jurassic.