Zoology 10th Edition by Stephen Miller,John Harley

Exercise 1

Evolutionary changes within the tetrapodomorph lineage that resulted in the movement onto land included changes in the skeleton and muscles for support and movement. Changes in a jaw mechanism and the neck skeleton promoted feeding on land. The evolution of an amniotic egg within the reptiliomorph lineage led to the evolution of reptiles (including birds) and mammals.
Why is knowledge of the sarcopterygian lineage so important in understanding animal evolution?