Coelacanths link between fish and amphibians. Dissemination 81st
These fish fossils 260 million years old (coelacanths) had fins with phalanges inside and its evolution (or any of his ancestors) allowed the appearance of the hands and arms as we know them today making them ancestors or related to the ancestors of the human being.
The sarcopterigios fish have bony skeleton of endochondral origin. They have enamel jaws and teeth. The skin is covered with scales; in extinct species, they posse layer on its surface. In the present species the caudal fin is dificerca, so backbone reaches the end of it and the membrane is developed symmetrically up and down of the same.
The fins are paired with crossed movement as with the current animals. The nervous system is also providing modern optic lobes of the brain, cerebellum is differentiated and its spine reaches the end of the tail fin. The heart has a venous sinus and another arteria, two atria and presents ventricle partial division; circulation has two circuits, one with lungs and organic also differentiated.
In coelacanths we find an interesting link in the evolution of marine animals to colonize land animals.