The shelly fauna and biostratigraphy of the lower Cambrian (provisional series 2, stage 4) Evjevik Member, Ringstrand Formation in the Mjøsa area, Norway

New, extensive fossil material collected in situ from the lower Cambrian Evjevik Member in the Mjøsa type area, southern Norway, allows a reevaluation of the faunal distribution and diversity of the ‘Ornamentaspis’ linnarssoni Zone. Described taxa include three holmiid, six ellipsocephalid and one eodiscoid trilobite in addition to five helcionelloid molluscs. A Holmia species with affinities to the Swedish H. lapponica is common in the Evjevik Member. Librigenae, thoracic segments and pygidia from the poorly known, but biostratigraphically important trilobite ’Ornamentaspis’ linnarssoni (Kiær, 1917) are documented for the first time. The species is redescribed and transferred to Ellipsocephalus. Helcionelloid molluscs are represented by Helcionella antiqua (Kiær, 1917), Stenotheca norvegica (Resser, 1938), Mackinnonia puppis n. sp., Mackinnonia? sp. and Latouchella sp. These are similar to taxa reported from coeval strata at Gislövshammar in southern Sweden and may prove to have biostratigraphical potential. The Holmia kjerulfi Zone, the Ellipsocephalus linnarssoni Zone and the Comluella? scanica–Ellipsocephalus lunatus Zone are readily recognised in the Lower Allochthon of the Mjøsa area and are in this report treated as distinctive, successive zones. New illustrations are provided of the brachiopod Magnicanalis rotundata (Kiær, 1917), together with the enigmatic fossil Mongolitubulus Missarzhevsky, 1977, recorded for the first time in Norway.