A review of the Mesozoic – Cenozoic acritarch genus Cyclopsiella Drugg & Loeblich Jr. 1967 emend. nov.

The acritarch genus Cyclopsiella is extant and ranges back to the Middle Jurassic. This genus cannot be assigned to any of the established acritarch subgroups and has a relatively simple morphology; species are often referred to using open nomenclature. This study provides a comprehensive analysis of Cyclopsiella and its different morphotypes and species, outlining their characteristics and similarities. Through an extensive literature review, this study identifies previous sources of taxonomic confusion, reevaluates the characteristics and stratigraphical utility of this genus, and discusses the significance of the constituent species for Mesozoic and Cenozoic biostratigraphy. A series of synonymies and emendations are proposed, and 10 species of Cyclopsiella are maintained. One new species, Cyclopsiella reticulata sp. nov., is described. This robust morphological investigation strengthens the biostratigraphical and palaeoecological potential of Cyclopsiella.