Character Details
fivefold symmetry
fivefold radial symmetry superimposed on bilateral symmetry
internal hydraulic system
internal hydraulic system with tube feet moved by fluid pressure
skeleton of calcite plates
skeleton made of monocrystalline plates of calcite
+-Deuterostomata
+-ECHINODERMATA <<<<< Taxon for this page
+-Hemichordata
+-Chordata
+-Urochordata
+-Cephalochordata
+-Craniata
+-Mixinoidea
+-Vertebrata
| +-Hyperoartia
| +-Jawless Fishes
+-Gnathostomata
+-Placodermi
+-Chondrichthyes
+-Teleostomi
+-Acanthodii
+-Osteichthyes
+-Actinopterygii
+-Sarcopterygii
| +-Coelacanthimorpha
| +-Dipnoi
+-Tetrapoda
+-Amphibia
+-Amniota
+-Synapsida
| +-Primitive Synapsids
| +-Mammalia
| +-Monotremata
| +-Marsupialia
| +-Eutheria
| +-Edentata
| +-Glires
| +-Archonta
| +-Insectivora
| +-Carnivora
| +-Ungulata
+-Reptilia
| +-Testudines
+-Diapsida
+-Primitive Diapsids
+-Sauria
+-Ichthyosauria
+-Sauropterygia
+-Lepidosauromorpha
+-Archosauromorpha
+-Crocodylomorpha
+-Pterosauria
+-Dinosauria
