Systematic revision of Onaraspis Öpik, 1968 (Trilobita) and related genera from Cambrian Series 2 of the Iberian Chains (Northeast Spain)

The trilobite genus Onaraspis has a history of taxonomic controversy. The species of this genus have been assigned to seven different families and divided into the genera Onaraspis and Myopsolenites by various authors. A careful systematic revision of Onaraspis from the Iberian Chains and other regions, in conjunction with related genera such as Luciaspis and Paulaspis , allows for assignment of these taxa to the Bathynotidae due to significant thoracic similarities. Additional genera from the Iberian Chains assigned to the Bathynotidae include Realaspis and Aragotus . Moreover, the morphometric analyses of Onaraspis species provide no morphological evidence for separation into two distinct genera. The variability of the characters included in the diagnosis of Myopsolenites , in conjunction with that of other characters representing the majority of the variation between species of the clade, is comparable between the two proposed genera. Consequently, Myopsolenites is regarded as a junior synonym of Onaraspis . Two new species, Onaraspis schmitzi n. sp. and Paulaspis schmidtthomei n. sp., are described. The Bathynotidae of the Iberian Chains show a wide stratigraphic range extending from the middle Marianian to upper Bilbilian (uppermost Stage 3 and Stage 4 of Cambrian Series 2). However, the majority of Onaraspis species are found in the upper part of the Cambrian Stage 4, which is more or less comparable with the Bathynotus kueichouensis - Ovatoryctocara sinensis Zone. An international correlation chart showing the stratigraphic ranges of genera assigned to the Bathynotidae is presented.