Protostomes

Lophotrocozoans

feeding structure found in 3.13 phyla, type of larvae common to many phyla, spiral pattern on cleavage in embryos

Phylum Platyhelminthes (Lophotrocozoans)

Flatworms (tapeworms, flukes), flattened body allows efficient gas exchange, incomplete gut

Phylum Annelida (Lophotrocozoans)

Segmented worms (leeches, earthworms), segmentation, chaetae (bristles made of chitin)

Mollusca (Lophotrocozoans)

Muscular foot (movement and support), visceral mass, mantle

Class Bivalvia (Mollusca)

Two shelled organisms, filter feeders, (clams, mussels, scallops, oysters)

Class Gastropoda (Mollusca)

Water to land transition, (snails, slugs, nudibranchs)

Class Cephalopoda (Mollusca)

Reduced or absent shell (squid, octopus, chambered nautilus, cuttlefish)

Ecdysozoans

Molt from hard cuticle/exoskeleton

Phylum Nematoda (Ecdysozoans)

Unsegmented, complete digestive track and hydrostatic skeleton, abundant, (roundworms)

Phylum Arthropoda (Ecdysozoans)

“Joint foot,” segmented regions called tagmata, exoskeleton of chitin, open circulatory system, (crickets, lobster)

Subphylum Chelicerata (Arthropoda)

Chelicerae (a pair of appendages) used for feeding, defense, sensory reception, 4 pairs of walking legs and 1 pair of chelicerae

Class Arachnida (Chelicerata)

Cephalothorax and abdomen, (spiders, mites, ticks, scorpions)

Subphylum Myriapoda (Arthropoda)

Many legs

Class Chilopoda (Myriapoda)

One set of legs per <30 segments, carnivorous, CENTIPEDES

Class Diplopoda (Myriapoda)

Two sets of legs per <200 segments, detritivores, MILLIPEDES

Subphylum Pancrustacea (Arthropoda)

Paired antennae, aquatic, (lobsters, crabs, shrimp, barnacles, isopods)

Subphylem Crustacea (Pancrustacea)

Cephalothorax and abdomen, two pairs of antennae, carapace (exoskeleton), mandibles

Class Insecta (Crustacea)

Head, thorax, abdomen, metamorphosis (larva to adult), many beetles