Icthyostega: Upper Devonian

PALEONTOLOGY: ON THE ADAPTATIONS OF AN ANCIENT AMPHIBIAN: "One of the defining events in the history of life was the emergence of terrestrial vertebrates from early fish. The oldest known fossils that illustrate the transition to land are those of Ichthyostega from the Upper Devonian of East Greenland. This 360-million-year-old amphibian resembled fish in many features of its skeleton, but possessed pelvic (hip) and pectoral (shoulder) girdles and limbs capable of supporting the body and allowing movement on land."