Biologists have suggested for a long time that reptiles evolved from fish-like ancestors - VCE - SSCE Biology - Question 5 - 2007 - Paper 1

The Tiktaalik fossil is considered a transitional form, which represents a significant evolutionary link between fish and terrestrial vertebrates. It exhibits characteristics of both groups, having features associated with fish, such as fins and scales, and features indicative of land animals, such as a mobile neck and forelimbs. This type of fossil provides vital evidence for the process of evolution and the transition from aquatic to terrestrial life.