Chapter 1: Introduction
Keeping Track of Life
Prokaryotes and Eukaryotes
Where Did Invertebrates Come From?
Where Do Invertebrates Live?
Changing Views of Invertebrate Phylogeny
A Final Introductory Message to the Reader

Chapter 2: Systematics, Phylogeny, and Classification
Phylogeny, Monophyly, Paraphyly, and Polyphyly
Homology
Apomorphy and Plesiomorphy
Challenges of Phylogenetic Inference
Constructing Phylogenies
Biological Classification
Nomenclature

Chapter 3: Introduction to the Animal Kingdom: Animal Architecture and Body Plans
Body Symmetry
Cellularity, Body Size, Germ Layers, and Body Cavities
Locomotion and Support
Cilia and Flagella
Feeding and Digestion
Excretion and Osmoregulation
Circulation and Gas Exchange
Nervous Systems and Sense Organs
Bioluminescence
Nervous Systems and Body Plans
Hormones and Pheromones
Reproduction
   
Chapter 4: Introduction to the Animal Kingdom: Development, Life Histories, and Origin
Evolutionary Developmental Biology: Evo-Devo
Eggs and Embryos
Life Cycles: Sequences and Strategies
The Relationships Between Ontogeny and Phylogeny
The Origin of the Metazoa
   
Chapter 5: Phylum Porifera: The Sponges
Taxonomic History and Classification
The Poriferan Body Plan
Some Additional Aspects of Sponge Biology
Poriferan Phylogeny

Chapter 6: Two Enigmatic Phyla: Placozoa and Ctenophora (The Comb Jellies)
Phylum Ctenophora
Taxonomic History and Classification
The Ctenophoran Body Plan
Ctenophoran Phylogeny
  
Chapter 7: Phylum Cnidaria: Anemones, Corals, Jellyfish, and Their Kin
Taxonomic History and Classification
The Cnidarian Body Plan
Cnidarian Evolutionary History
  
Chapter 8: A Brief introduction to the Bilateria and Its Major Clades
Deuterostomes and Protostomes
  
Chapter 9: Phylum Xenacoelomorpha. Basal Bilaterians
The Basal Bilaterian
Phylum Xenacoelomorpha
Subphylum Acoelomorpha
Class Acoela
The Acoel Body Plan
Class Nemertodermatida
The Nemertodermatid Body Plan
Subphylum Xenoturbellida
The Xenoturbellid Body Plan
  
Chapter 10: Protostomia, Spiralia, and the Phylum Dicyemida
Spiralia and Ecdysozoa
The Phylum Dicyemida (= Rhombozoa)
Anatomy and Biology of Dicyemidans
Life Cycles

Chapter 11: Gnathifera. The Phyla Gnathostomulida, Rotifera (including Acanthocephala), Micrognathozoa, and Chaetognatha
Phylum Gnathostomulida: The Gnathostomulids
The Gnathostomulid Body Plan
Phylum Rotifera: The Free-Living Rotifers
The Rotifer Body Plan
Body Cavity, Support, and Locomotion
Nervous System and Sense Organs
Reproduction and Development
Phylum Rotifera, Subclass Acanthocephala: The Acanthocephalans
The Acanthocephalan Body Plan
Phylum Micrognathozoa: The Micrognathozoans
The Micrognathozoan Body Plan
Phylum Chaetognatha
Chaetognath Classification
The Chaetognath Body Plan
Reproduction and Development
   
Chapter 12: Platytrochozoa and Two Enigmatic Phyla: Entoprocta and Cycliophora
Phylum Entoprocta: The Entoprocts
The Entoproct Body Plan
Phylum Cycliophora: The Cycliophorans
   
Chapter 13: Introduction to the Lophotrochozoa, and the Phylum Mollusca
The Lophotrochoza
Phylum Mollusca
Taxonomic History and Classification
The Molluscan Body Plan
Molluscan Evolution and Phylogeny
  
Chapter 14: Phylum Nemertea: The Ribbon Worms
Taxonomic History and Classification
The Nemertean Body Plan
Nemertean Phylogeny
   
Chapter 15: Phylum Annelida. The Segmented (and Some Unsegmented) Worms
Taxonomic History and Classification
The Annelid Body Plan
Sipuncula: The Peanut Worms
Sipunculan Classification
The Sipunculan Body Plan
Thalassematidae: The Spoon Worms
Siboglinidae: Vent Worms and Their Kin
Siboglinid Taxonomic History
The Siboglinid Body Plan
Hirudinea: Leeches and Their Relatives
The Hirudinean Body Plan
Orthonectida: Extremely Simplified Annelids
Annelid Phylogeny
  
Chapter 16: The Lophophorata: Phyla Phoronida, Bryozoa, and Brachiopoda
Taxonomic History of the Lophophorates
The Lophophorate Body Plan
Phylum Phoronida: The Phoronids
The Phoronid Body Plan
Phylum Bryozoa: The Moss Animals
The Bryozoan Body Plan
Phylum Brachiopoda: The Lamp Shells
The Brachiopod Body Plan
  
Chapter 17: Rouphozoa: The Phyla Platyhelminthes (Flatworms) and Gastrotricha (Hairy-Bellied Worms)
Introduction to Rouphozoa
The Phylum Platyhelminthes (Flatworms)
Taxonomic History and Classification
The Platyhelminth Body Plan
Platyhelminth Phylogeny
Phylum Gastrotricha: The Gastrotrichs, or Hairy-Bellied Worms
The Gastrotrich Body Plan
Reproduction and Development
  
Chapter 18: Introduction to Ecdysozoa: Scalidophora (Phyla Kinorhyncha, Priapula, Loricifera)
Introduction to Ecdysozoa
The Scalidophora
Phylum Kinorhyncha: The Kinorhynchs, or Mud Dragons
The Kinorhynch Body Plan
Phylum Priapula: The Priapulans, or Penis Worms
Priapulan Body Plan
Nervous System and Sense Organs
Phylum Loricifera: The Loriciferans
  
Chapter 19: Nematoida: Phyla Nematoda and Nematomorpha
Phylum Nematoda: Roundworms
Nematode Classification
The Nematode Body Plan
Life Cycles of Some Parasitic Nematodes
Phylum Nematomorpha: Horsehair Worms and Their Kin
The Nematomorph Body Plan
  
Chapter 20: Panarthropoda and the Emergence of the Arthropods. Tardigrades, Onychophorans, and the Arthropod Body Plan
Phylum Tardigrada
The Tardigrade Body Plan
Phylum Onychophora
The Onychophoran Body Plan
An Introduction to the Phylum Arthropoda
The Arthropod Body Plan and Arthropodization
The Evolution of Arthropods
  
Chapter 21: Phylum Arthropoda. Subphylum Crustacea: Crabs, Shrimps, and Their Kin
Classification of the Crustacea
Synopses of Crustacean Taxa
The Crustacean Body Plan
Crustacean Phylogeny
  
Chapter 22: Phylum Arthropoda. Hexapoda: Insects and Their Kin
The Hexapod Body Plan
Hexapod Evolution
  
Chapter 23: Phylum Arthropoda. Subphylum Myriapoda: Centipedes, Millipedes, and Their Kin
Myriapod Classification
The Myriapod Body Plan
Myriapod Phylogeny
  
Chapter 24: Phylum Arthropoda. The Chelicerata
Synopses of Living Chelicerate Groups*
The Euchelicerate Body Plan
The Class Pycnogonida
The Pycnogonid Body Plan
Chelicerate Phylogeny
  
Chapter 25: Introduction to Deuterostomia, and the Phylum Hemichordata
Introduction to the Deuterostomia
Phylum Hemichordata: Acorn Worms and Pterobranchs
The Hemichordate Body Plan
Class Enteropneusta (Acorn Worms)
Class Pterobranchia (Pterobranchs)
Hemichordate Fossil Record and Phylogeny
  
Chapter 26: The Phylum Echinodermata
The Phylum Echinodermata
Taxonomic History and Classification
The Echinoderm Body Plan
Echinoderm Phylogeny
  
Chapter 27: Phylum Chordata: Cephalochordata and Urochordata
Phylum Chordata, Subphylum Cephalochordata: The Lancelets
The Cephalochordate Body Plan
Phylum Chordata, Subphylum Urochordata: The Tunicates
The Tunicate Body Plan
Chordate Phylogeny
   
Chapter 28: Perspectives on Invertebrate Phylogeny