Kottixerxes belongs to a fascinating group of problematic arthropods named Euthycarcinoidea. The current thinking is that they are marine cousins distantly related to insects and myriapods. When Schram first described Kottixerxes in 1971, the Euthycarcinoidea were only know from 2 Triassic aged sites in Germany and Australia. At the time it was described, Kottixerxes was the oldest known Euthycarcinoid. Since that time, Euthycarcinoidea have been found in strata dating back to the Cambrian. In