The Late Cambrian (Steptoean) Trilobite Genus Bynumina Resser, 1942, in North America

Bynumina Resser, 1942, is the youngest representative of the family Kingstoniidae Kobayashi, 1933. The genus is defined by synapomorphies that include an unequally convex pygidial axis in which at least the first axial ring stands well above the level of the weakly arched posterior rings. It comprises six species, two of which are new; B. kimbellorum sp. nov., from the Honey Creek Formation of Oklahoma, is formally named. All species occur in a relatively narrow stratigraphic interval in the lower half of the upper Steptoean Elvinia Zone and have potential for biostratigraphic correlation.