Please use Citations and Cite References
There are nine major animal phyla (actually there are over thirty that are recognized by taxonomists so consider yourself getting off lucky). Choose two phyla that you find particularly interesting (while trying avoid combinations picked by other class members). Give common examples of each phylum and distinguish among them relative to types of tissues/tissue layers (none, diplobastic, triplobastic), body symmetry (assymetrical, radial symmetry, and bilateral symmetry) and presence and type of body cavity (acoelomate, pseudocoelomate, coelomate). Be careful not to confuse digestive cavities with body cavities. They are very different things. Briefly, discuss why the phyla would be similar or different for these characters based on evolutionary relationships and environmental influences.