Ichthyostega
From Tardis Wiki, the free Doctor Who reference
An Ichthyostega was a type of Earth creature, the first true amphibian of that world.
In a surreal event, the Seventh Doctor watched a lungfish grow stubby legs and become an Ichthyostega, two million years early by his count. It continued to change, losing gill slits and growing longer legs, claws and teeth, becoming a reptile. (PROSE: Transit)
