This group includes vertebrates. These animals all have a skeleton and a skull to protect the brain. They include armored fish, sharks, bony fish, amphibians, reptiles, birds, and mammals.

Classes:

Cephalaspidomorphi

Pteraspidomorphi

Placodermi

Chondrichthyes

Acanthodii

Osteichthyes

Reptilia

Aves

Mammalia

For more information:

http://www.ucmp.berkeley.edu/vertebrates/vertintro.html