The famous coelacanth’s stumpy fins are believed to have evolved so that it could walk on land.
This fish also developed the ability to gulp air and absorb it through its gullet, or throat. So the coelacanth could not only walk on land, it could breathe.
Another fish that developed the ability to gulp air is the lungfish. A few types of lungfish still exist in Africa, Australia, and South America.
Fossils show that other fishes began to find homes in shallower waters and wet mud along the shores.
Over a period of 50 million years, their offspring became comfortable on the damp land above the waterline. These were the earliest tetrapods, or four-legged animals.