Anopolenus henrici Salter, a middle Cambrian (Drumian) centropleurid trilobite from the Alum Shale Formation of Scandinavia

Centropleurid trilobites include five genera of which Centropleura Angelin, Anopolenus Salter, Clarella Howell and Luhops Šnajdr are known from eight species in the traditional middle Cambrian (Miaolingian Series, Drumian Stage) of Sweden and Denmark (Bornholm). Beishanella Xiang & Zhang has not been recorded in Scandinavia so far, and no centropleurids have been reported from Norway. Of these taxa, only Centropleura is common in Scandinavia. Two pygidia previously identified as Centropleura sp. and Anopolenus sp. from erratics in Germany and Bornholm, respectively, as well as a new pygidum from Scania in Sweden are here identified as Anopolenus henrici Salter. Elsewhere, the species is known from Wales, Avalonian Canada, Siberia, Alaska, and Sardinia, occurring in the A. atavus and P. punctuosus zones (the former in Siberia only). The presence of this species increases the known diversity of Centropleuridae in Scandinavia and is important for correlation between Baltica and Avalonia.