Politicurus and a related genus of hintzecurine trilobites from the late Skullrockian (Tremadocian Early Ordovician) of western Utah and southeastern Idaho

Politicurus Adrain et al., 2003, is a genus of Early Ordovician trilobites from North America that is currently represented in the literature by a single species. Initial work in the 1950s involved the description of diverse trilobite faunas from southeastern Idaho, western Utah, and eastern Nevada. Recently, continued collection of limestones containing exceptionally preserved fossils has allowed for more in-depth study of Early Ordovician trilobite diversity and evolutionary history. Here, eight new species of Politicurus are described, including seven that are well enough represented by fossil remains to be formally named and one that is described but not named due to insufficient representation. An additional species, representing a closely related new genus, Praepoliticurus n. gen., is also introduced.

Members of Politicurus have small tails, mostly smooth exoskeletons, and bear long spines on the cephalon and sixth segment of the thorax. Analysis of the morphology of these species provides an initial hypothesis of the evolutionary relationships within Politicurus and Praepoliticurus. Four species of more tuberculate trilobites form a group within Politicurus that share unique features, including comparatively slender spines, a significantly bowed lateral border of the librigena, reduced preglabellar field, and highly dorsally curved anterior border of the cranidium.