Answer:
All invertebrates except echinoderms are protostomes. Protostomes include the phylum: coelenterata, ctenophora, platyhelminths, nematyhelminths, annelida, arthropoda and mollusca.
Step-by-step explanation:
Echinoderms and chordates have tube within tube type of body plan which has evolved along deuterostomic evolutionary line. Other similarities between echinoderms and chordates (which includes vertebrates) are:
-They possess a true coelom called enterocoelom.
- They have mesodermal skeleton made of calcareous plates or ossicles.