Spineless Wonders: A Survey of the Invertebrates

Amoebas, Foraminifera, Radiolaria, etc. Phylum: Protista Amoebas, Foraminifera, Radiolaria, etc.

Phylum Porifera (Sponges) Single layer of tissue (collared cells)

Phylum Cnidaria / Coelenterata 2 layers of tissue: ectoderm, endoderm

2 tissue layers: ectoderm, endoderm Phylum Cnidaria / Coelenterata Hydra hard corals sea pens sea anemones soft corals jellyfish 2 tissue layers: ectoderm, endoderm

“Worms” - 3 tissue layers ectoderm, mesoderm, endoderm

Phylum Brachiopoda (“arm foot”) Key Features: pedicle, gut, muscles, lophophore

Phylum: Bryozoa (“moss animals”) Key Features: Colonial Habit Have Lophophore

Key Features: 5-fold symmetry, calcite plates Phylum Echinodermata (“spiny skin”) Sea urchins Brittlestars Crinoids Starfish Sea cucumbers Key Features: 5-fold symmetry, calcite plates

(hypothetical ancestral mollusc) Phylum Mollusca HAM (hypothetical ancestral mollusc) Key Features: gut mantle cavity radula (rasper) gills foot

Phylum: Arthropoda Insects Spiders Crabs Lobsters Barnacles Etc. trilobites eurypterids Key Features: Jointed appendages 3-fold division of body (head, thorax, abdomen) scorpions shrimps

Phylum Mollusca Gastropods Bivalves Cephalopods (squids, octopuses, cuttlefish, ammonoids)

(preoral lobe, collar, trunk) Phylum: Hemichordata Key Characteristics: 3-part division of body (preoral lobe, collar, trunk) Pharynx Gill slits Stomochord Pterobranchs Graptolites Acorn worms

Sea squirts and salps (Urochordates) Phylum: Chordata Key Features: notochord dorsal nerve cord, pharynx gills slits post-anal tail Sea squirts and salps (Urochordates) Amphioxus (lancelet) (Cephalochordates)

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