Clade for Kingdom ANIMALIA (Metazoa)
Revised clade from Tree of Life for Kingdom Animalia (after Ruppert & Barnes 1994 p. 1052).
========================================== Porifera (sponges) | | =================================== Cnidaria (jellyfish, anemones, corals, etc.) | | | | ================================ Ctenophora (comb-jellies) | | | | | | =(placement uncertain)== pseudocoelomates(nematodes,rotifers,etc.) | | | | | | | | +==================== Platyhelminthes(flatworms,tapeworms,etc.) | | | | | <<===| | | =P*=| | ================= Nemertea (ribbon worms) | | | | | | | | | | | | | | ======== Sipuncula (peanut worms) | ====| | | ===| | ======| | | | | | | | | ======== Mollusca(snails, clams, squids, etc.) | | | | | =C*=| | | | | | | | | ======== Echiura (proboscis worms) | | | | | ===| | | | | | | | ===| ===== Pogonophora (beard worms, vent worms) | | ===| | | | ===| | | | | ===| ===== Annelida(segmented worms) | | | | | ===| | | | ======== Onychophora (velvet worms) | | | ===| | | | ======== Arthropoda(insects, spiders, crabs, etc.) | =B*=| | | ======================== Chaetognatha (arrow worms) | | | | =D*=| ===================== lophophorates (bryozoans, brachiopods, etc.) | | | | ===| ================== Echinodermata(starfish, urchins, etc.) | | | | ===| =============== Hemichordata (acorn worms, pterobranchs) | ===| | =============== Chordata (sea squirts, vertebrates, etc.) | =====(phyla of uncertain affinity)===== Placozoa, Monoblastozoa, Rhomobozoa, Orthonectida*Traits supporting each clade (** plesiomorphic- a primitive state, not unique to clade):
B= BILATERIA: a) bilateral symmetry,b) cephalization, c) triploblastic organization (extensive mesoderm), d) organ-system level of organization, e) protonephridia
P= PROTOSTOMIA: a) spiral, determinate cleavage, b) mesoderm from mesenchyme cells, c) mouth (and sometimes anus) from blastopore, d) multiciliated cells
C= COELOMATE PROTOSTOMES: a) coelom via schizocoely
D= DEUTEROSTOMIA: a) radial, indeterminate cleavage**, b) coelom via enterocoely, c) blastopore yields anus, d) tripartite coelom & body plan, e) monociliated cells (primitively)
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Copyright © 1997 by A. Richard Palmer. All rights reserved. (revised April 11, 1997)