New finds of trilobites and brachiopods are described from two horizons in the autochthonous/parautochthonous Hardangervidda Group. The occurrence of the trilobites Lejopyge armata (Linnarsson) and Andrarina costata (Angelin) indicates, for the first time, a late mid-Cambrian (Lejopyge /aevigata Zone)
age for part of the 'Alum Shale' (Bjørno Member of the Låven Formation) on Hardangervidda. Brachiopods from the younger Bjørnaskalle Formation include orthides, a clitambonitide and Antigonambonites of the planus species group of Opik and are indicative of a late Arenig- early Llanvirn age.
Both faunas indicate the most westerly known extension of Cambrian and Ordovician rocks on the Baltic platform. But whilst the uniformity of the 'Alum Shale' facies across the platform is confirmed, the upper Arenig-lower Llanvirn rocks differ from coeval strata elsewhere in the autochthon.