Publisher's Synopsis
There are many interesting aspects to the anatomy of fish that are worth exploring. Why? Because the evolution of fish actually sets the stage for the evolution of every other vertebrate on earth!
Fish Evolution
Nearly all of the features that amphibians, reptiles, birds, and mammals have are adaptations and alterations from anatomical features fish first developed. Even lungs have their roots in formerly aquatic features that fish still use today!
The first fish are a very strange lot. Many had no jaws, for example, and simple spinal columns formed mostly or entirely of cartilage. Most also had thick, bony plates of armor at first; the small scales we associate with modern bony fish were a later development.
