The First Tetrapods Step Ashore

What happened

During the Devonian, some lobe-finned fish evolved into the first four-limbed vertebrates, the tetrapods. Transitional fossils such as Tiktaalik — with a mix of fish and land-animal features including sturdy limb bones, a mobile neck, and lungs — capture this move from water toward land.

Why it matters

The emergence of tetrapods began the vertebrate conquest of the land, the ancestral line leading to amphibians, reptiles, birds, and mammals.

Sources

• Natural History Museum. Prehistoric fish: significant species and the move to land · Reputable source