Evolution of organ systems in the Crustacea: Mystacocarida and Cephalocrida in retrospect
The morphology of the internal organs of two representative species of the crustacean classes Mystacocarida, Derocheilocaris typica (Pennak & Zinn, 1943), and Cephalocarida, Hutchinsoniella macracantha (Sanders, 1955), has been studied ultrastructurally from 1990 onwards. A review of the subject offers a unique opportunity to compare and contrast the two taxa at a time when their key positions