Cladogram for KINDOM ANIMALIA (=Metazoa)
Modified from Tree of Life for Kingdom Animalia (after Ruppert & Barnes 1994 p. 1052).
========================================== Porifera (sponges) | | =================================== Cnidaria (jellyfish, anemones, corals, etc.) | | | | ================================ Ctenophora (comb-jellies) | | | | | | ======================== Platyhelminthes (flatworms, tapeworms,etc.) | | | | | | | | =(branch uncertain)== Aschelminthes (nematodes, rotifers,etc.) | | | | | <<=M=| | | =P==| | ================= Nemertea (ribbon worms) | | | | | | | | | | | | | | ======== Mollusca (snails, clams, squids, etc.) | =E==| | | ===| | ======| | | | | | | | | ======== Sipuncula (peanut worms) | | | | | =C==| | | | | | | | | ===== Annelida (segmented worms) | | | | | ===| ===| | | | | | | ===| ===== Pogonophora (beard worms, vent worms) | | ===| | | | | | | | | ===| ======== Echiura (proboscis worms) | | | | | ===| | | | ======== Onychophora (velvet worms) | | | ===| =B==| ======== Arthropoda (insects, spiders, crabs, etc.) | | | ======================== 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) radial symmetry** c) monociliated cells** d) radial, indeterminate cleavage e) blastula stage larva f) diplosome** g) type IV collagen b) diploblastic organization c) gastrula stage d) blind gut (no anus) b) cephalization c) triploblastic organization (extensive mesoderm) d) organ-system level of organization e) protonephridia |
b) mesoderm from mesenchyme cells c) fate of first derm cell set at 5th cleavage d) mouth (and sometimes anus) from blastopore e) multiciliated cells f) trochophore-like larva b) coelom via schizocoely c) complete gut (anus present)** b) mesoderm from epithelial cells c) coelom via enterocoely d) blastopore yields anus e) tripartite coelom & body plan f) monociliated cells** |