Biology 38

Cladogram for KINGDOM ANIMALIA (=Metazoa)



 ~ This page is a modification of the Cladogram for Kingdom Animalia assembled by Dr. A. Richard Palmer for his Survey of the Invertebrates (Zoology 250) course at the University of Alberta, Canada. Both this page and his are modifications of the Tree of Life for Kingdom Animalia.

 ~ The tree presented below follows Brusca and Brusca's Invertebrates,1990 (pg. 882). It differs from Dr. Palmer's cladogram primarily in the position of the Echiurans. You should compare this cladogram to his. You should also note that the relationships of many of the groups in these and other cladograms you are likely to view are unknown/ still under debate.



     ======================================== Porifera(sponges)
     |
     |      ================================= Cnidaria (jellyfish, anemones, corals, etc.)
     |      |
     |      |  ============================== Ctenophora (comb-jellies)
     |      |  |
     |      |  |       ====================== Platyhelminthes (flatworms, flukes, tapeworms, etc.)
     |      |  |       |
     |      |  |       |  ===(Uncertain!)==== Aschelminthes (pseudocoelomates: nematodes,rotifers,etc.)
     |      |  |       |  |
<==M=|      |  |   =P==|  |   =============== Nemertea (ribbon worms) 
     |      |  |   |   |  |   |
     |      |  |   |   |  |   |     ========= Sipuncula (peanut worms)
     |      |  |   |   |  |   |     |
     |  =E==|  |   |   ===|   |  ===|======== Echiura (proboscis worms)
     |  |   |  |   |      |   |  |  |
     |  |   |  |   |      =C==|  |  ========= Mollusca (snails, clams, squids, etc.)
     |  |   |  |   |          |  |
     |  |   |  |   |          |  |     ====== Annelida (segmented worms)           
     |  |   |  |   |          ===|     |       
     |  |   ===|   |             |  ===|   == Vestimentifera
     |  |      |   |             |  |  |===|     
     |  |      |   |             |  |      == Pogonophora (beard worms, vent worms)                       
     |  |      =B==|             ===|        
     |  |          |                |  ====== Onychophora (velvet worms)
     ===|          |                ===|     
        |          |                   ====== Arthropoda (insects, crabs, spiders, etc.)            
        |          |      
        |          |   ====================== Chaetognatha (arrow worms)
        |          |   |
        |          =D==|  =================== lophophorates (bryozoans, brachiopods, etc.)
        |              |  |
        |              ===|  ================ Echinodermata (starfish, urchins, sea cucumbers, etc.)
        |                 |  |
        |                 ===|  ============= Hemichordata (acorn worms, pterobranchs)
        |                    ===|
        |                       ============= Chordata (sea squirts, vertebrates, etc.)
        |
        ====(phyla of uncertain affinity)==== Placozoa, Monoblastozoa, Rhomobozoa, Orthonectida




Traits supporting each clade:

M= METAZOA, E= EUMETAZOA, B= BILATERIA, P = PROTOSTOMIA, C = COELOMATE PROTOSTOMES,
D= DEUTEROSTOMIA