3.10: Animalia- body plans, phyla and classes
From Georges Cuvier times, highest animal groups (phyla) are understood as different body plans (Fig. 3.10.2).
There are some important animal phyla with notes about their body plans. Note that most of mentioned characters do not belong to the 100% of phylum species. As biology is a science of exceptions, this is normal. The following table lists many of animal phyla and also classes of chordates. Look also on “split pyramid” scheme (Fig. 3.10.1).
Subregnum Spongia : no symmetry
Phylum 1. Porifera: sitting filtrators with skeletal spicules (H)
Subregnum Cnidaria : radial symmetry, stinging cells
Phylum 2. Anthozoa: sitting, colonial, with skeleton (I)
Phylum 3. Medusozoa: swimming, solitary, soft (A)
Subregnum Bilateria : bilateral symmetry, likely originated from crawling habit
Infraregnum Deuterostomia : with specific embryogenesis
Phylum 4. Echinodermata: small-plate exoskeleton, secondary radial, water-vascular appendages (E)
Phylum 5. Chordata: head and tail, gills in pharynx, axial skeleton (B)
Subphylum Vertebrata : vertebral column
Pisces : fish-like, gills
Classis 2. Chondrichtyes : cartilaginous, live in ocean
3. Actinopterygii : boned, rayed fins
4. Dipnoi : boned, thick fins, gills and lungs
Tetrapoda : four legs
Superclassis Anamnia : water eggs
Superclassis Amniota : terrestrial eggs
Classis 6. Reptilia : no feathers, four-pedal
7. Aves : feathers, bipedal
8. Mammalia : grinding jaws, fur, milk
Infraregnum Protostomia : specific embryogenesis
Superphylum Spiralia : worms, mollusks and alike
Phylum 6. Mollusca: shell, body straight (F)
Phylum 7. Lophophorata: shell and alike, body curved (J)
Phylum 8. Annelida: naked, segmented (G)
Superphylum Ecdysozoa : molting, with chitinous cuticle
Phylum 9. Nemathelminthes: worms with bending motion and primary cavity (C)
Phylum 10. Arthropoda: both body and appendages segmented (D)
Classis 1. Chelicerata : spiders, ticks, mites, scorpions
2. Malacostraca : crabs, lobsters, shrimp
3. Hexapoda : insects and alike