Invalid names: Ctenacanthus deflexus St. John and Worthen 1883 [objective synonym], Ctenacanthus harrisoni St. John and Worthen 1883 [objective synonym], Ctenacanthus maximus de Koninck 1878 [synonym], Ctenacanthus salopiensis Davis 1883 [objective synonym], Ctenacanthus spectabilis St. John and Worthen 1875 [objective synonym], Ctenacanthus tenuistriatus Agassiz 1836 [objective synonym], Ctenacanthus varians St. John and Worthen 1875 [objective synonym]