This is the evolutionary tree of today's top hunters,sharks,the most modern shark(a) is the closest to the current one we see today, as we go farther back, we see that the shark becomes more reptile-like and clearly shows that in the tetra-pod(g), Eryops,who is currently extinct. more currently, the more fish like creature, Acathostega(f), is also a tetra-pod,an extinct tetra-pod.Further along is Panderichthys(e), an extinct fish. Now to another extinct fish,Eusthenopteron(d),almost back to sharks, the lungfish(c) is still alive today. Nearing the journey of our evolution adventure,coelacanth(b) is also still alive. As we look through the evolutionary tree,we see that the structural similarities in the fins/legs of these creatures are very similar except for our tetra-pods,who have more finger like pieces which seemed to disappear after Panderichthys(e) and seemed to become more fin-like, most likely for ocean life.