Metazoa Phylogenetic Tree

before ecdysozoa

ecdysis - shedding skin or outer cuticle

ecdysozoa

nematoda and arthropoda

before arthropoda

exoskeleton, segmentation

before deuterostomes

blastopore becomes anus, radial/regulative cleavage

protostomes

mollusca, annelida, meatoda, arthropoda

deuterostomes

Echinodermata, chordata

before Cnidaria

cnidocytes, planula larva, radial symmetry, incomplete two-way gut

before bilateria

complete one-way gut, triploblasty, bilateral symmetry

before protostomes

blastopore becomes mouth

before lophotrochozoa

trochophore larva, spiral/mosaic cleavage

lophotrochozoa

mollusca and annelida

before mollusca

mantle and shell, radula

before annelida

paired setae, segmentation

before first node of tree

blastula, multicellularity, collagen, proteoglycans, unique cell-cell junctions

before porifera

spicules

before Ctenophora

complete one-way gut

echinodermata

calcite endoskeleton, water vascular system, tube feet, pentaradial symmetry

chordata

postanal tail, notochord, dorsal/hollow nerve cord, segmentation