The Furongian trilobite Irvingella from Jamtland and angstrom ngermanland, Sweden

New material of Irvingella from central Sweden includes a cranidium of Irvingella major which is associated with fragmentary olenid trilobites that represent the Parabolina brevispina Subzone of the P. spinulosa Zone. This affords a direct correlation between the olenid trilobite zonation of Baltica and the Irvingella major Zone at the base of the Sunwaptan Stage in Laurentia. Several topotypic cranidia of Irvingella suecica Westergard confirm the features of that species but do not provide a direct indication of its position within the olenid zonal succession.