Phylogeny of the Invertebrates

The tree below was recently redrawn from Dunn et al (2008). The animal phyla represented have been selected for familiarity and to provide context for phyla often exhibited in aquaria and that might be seen at various exhibits at the Fort Worth Zoo. My selection of which "minor phyla" to include both on the tree and in the list below is frankly idiosyncratic. Below you will find a listing of the names of each phylum, and examples of its more common members. Some phyla are identified by their common names. Links to representative animals for phyla that can be seen at the zoo have been provided, both from the phylum list and from the tree.

Contrary to my usual practice at WhoZoo, I have also included links from the list to discussions of less familiar phyla at other web sites; these are marked with an asterisk(*). Sources for information on these animals are included in the source list below the tree. Only animals that exhibited at the Fort Worth Zoo have been linked from the tree itself. Note: with the closing of the James R. Record Aquarium, some animals can no longer be seen at the Fort Worth Zoo.

• Phylum Porifera: the *sponges
• Phylum Cnidaria: anemones, jellyfish and corals
• Phylum Platyhelminthes: the flatworms
• Phylum Echinodermata: sea stars, sea urchins, sand dollars, sea lilies
• Phylum Chordata, subphylum Urochordata: the *sea squirts
• Phylum Chordata, subphylum Cephalochordata: the *lancelets
• Phylum Chordata, subphylum Vertebrata: the vertebrates
• Phylum Mollusca: bivalves, snails, *octopuses and squid
• Phylum Pogonophora: this relatively unfamiliar phylum has been included because the Vestimentiferan worms -- the giant red tube-building worms that colonize the waters around *deep sea volcanic vents -- are closely related to them.
• Phylum Annelida: earthworms and fanworms
• Phylum Rotifera: the *rotifers
• Phylum Nematoda: the *nematodes
• Phylum Onychophora: the *velvet worms
• Phylum Tardigrada: the *water bears -- charming, stumpy-legged segmented animals
• Phylum Arthropoda: because the ranks of the major taxa within this large and successful group are variously defined, I have included the groups without a rank assignment below:
  
  • Myriapods: centipedes and millipedes
  • Insects: beetles, flies, butterflies, roaches, ants and bees, bugs, grasshoppers, phasmids (AKA stick insects)and other insects.
  • Crustaceans: crabs, shrimp and lobsters, and the giant isopods.
  • Merostomata: the horseshoe crabs
  • Arachnida: spiders, scorpions, ticks and mites.
  • Trilobita: the *trilobites -- extinct arthropods commonly found as fossils.

Additional notes: Deuterostomes are animals whose embryos develop a mouth as a secondary embryonic structure opposite to the blastopore, which opens into the primitive gut. Protostomes are animals that develop their mouths from or very near to the blastopore. Ecdysozoans are animals that molt their cuticles or exoskeletons as they grow. Lophotrochozoans are a group of animals that have either a trochophore (toplike) larva or a feeding organ (lophophore) composed of a ring of ciliated tentacles.

Invertebrate Tree

Fish Tree

Tetrapod Tree

Reptile Tree

Bird Tree

Mammal Tree

Sources and links to offsite information about invertebrates:

• Allen G. Collins, Brian R. Speer and Ben Waggoner. The Metazoa: University of California Museum of Paleontology.
• Allen G. Collins and Ben Waggoner.Introduction to the Porifera. University of California Museum of Paleontology
• Casey Dunn et al, 2008.Broad phylogenetic sampling improves resolution of the animal tree of life. Nature Online (5 March 2008) .
• Ben Waggoner and B. R. Spear. Introduction to the Flatworms. University of California Museum of Paleontology.
• James Wood. The Cephalopod Page
• Wim van Egmond and Jan Parmentier. Sea Squirts, Our Distant Cousins
• Ben Waggoner. Introduction to the Lancelets. University of California Museum of Paleontology.
• Hot Vents. Marine Biology at State University of New York.
• Roy Winsby. Rotifers and How to Find Them.
• Ben Waggoner and Brian R. Speer. Introduction to the Nematoda. University of California Museum of Paleontology.
• Ben Waggoner and Allen G Collins. Introduction to the Onychophora. University of California Museum of Peleontology.
• Phil Greaves. Tardigrades.
• Sam Gon III. A Guide to the Orders of Trilobites
• University of California Museum of Paleontology. Introduction to the Lophotrochozoa
• University of California Museum of Paleontology. Introduction to the Ecdysozoa.