Phylum Echinodermata

Class Asteroidea: starfishes, or sea stars

Class Ophiuroidea: brittle stars and basket stars

Class Echinoidea: sea urchins and sand dollars

Class Holothuroidea: sea cucumbers

Class Crinoidea: sea lilies and feather stars

Phylum Chordata

Subphylum Tunicata (Urochordata) – sea squirts, or tunicates, and salps

Subphylum Cephalochordata – lancelets (amphioxus)

Subphylum Vertebrata – the vertebrates

Class Petromyzontida – lampreys

Class Myxini – hagfishes Class

Chondrichthyes – sharks, skates and rays

Class Sarcopterygii – lobe-finned fishes

Class Actinopterygii – ray-finned fishes