Comparative analysis of six common foraminiferal species of the genera <i>Cassidulina</i>, <i>Paracassidulina</i>, and <i>Islandiella</i> from the Arctic–North Atlantic domain

Abstract. Morphologically similar benthic foraminiferal taxa can be difficult to separate. Aside from causing issues in taxonomy, incorrect identifications complicate our understanding of species-specific ecological preferences and result flawed palaeoenvironmental reconstructions geochemical results. Over the years, a number studies have grouped together several key Arctic–North Atlantic species various combinations, despite their distinct environmental and/or stratigraphical differences, great confusion literature. These include Cassidulina laevigata, neoteretis, teretis, Paracassidulina neocarinata, Islandiella helenae, norcrossi. Here, we provide for first time detailed comparison these taxa. We present compilation original descriptions, along with clear, illustrated guidelines on how separate circumvent taxonomic confusion. acknowledge that some features cannot easily seen standard low-powered microscope, especially if specimens are not well preserved. In those cases, recommend following actions: (i) always strive make precise identification at least differentiate between three genera; (ii) where C. neoteretis teretis separated, context does obvious, belonging should reported as teretis/C. neoteretis; (iii) sample confidently assigned specific or Cassidulina, spp. spp., followed by naming most dominant brackets. The improved Paracassidulina, will ensure development better affinities taxa, consequently resulting more accurate data.