Class Ambphibia arose from Crossopterygian and Rhipidistian ancestors. They have lungs and skin used as adult respiratory organs. When they are larvae, they have gills. When they get older, however, the majority developlungs. They have two atria and one ventircle in their heart; it is three chambered. Their skin is either naked or has a bony dermal element. They are alos ectothermic which means they have to regulate their body temperature by moving to new places in their environment in a an attempt to control body temp. Finally, eggs are laid in a jelly like protective coating.
Spotted Salamander (Ambystoma Maculatum)
Diversity of vertebrates. (2010). Retrieved from http://www.shsu.edu/~bio_mlt/Chapter3.html
