Multiple choice Which of the following is an echinoderm? Chiton Balanoglossus Antedon Scoliodon Reveal answer Fill a bubble to check yourself C Correct answer Explanation Antedon is a genus of crinoids (sea lilies), which belong to the phylum Echinodermata. Chiton is a mollusk, Balanoglossus is a hemichordate, and Scoliodon is a cartilaginous fish (Chondrichthyes).