| There are three separable conceptions of the extent of the period of the diversification of the animal phyla. |
| The four phyla discussed here have not found their established positions in the zoological system. |
| On the bright side, if students can get into the vertebrate examples discussed here, maybe some will plumb deeper into other phyla and kingdoms. |
| The specific process of apoptosis first appeared with the evolution of metazoan animals and has been well conserved in all animal phyla. |
| Arthropods, chordates and annelids are the three segmented phyla in the animal kingdom. |
| More complex thalloid compressions may display morphologies that are localized within a given phylum but convergent among phyla. |
