Tiktaalik is a “fishapod,” a type of ancient fish that represents the evolutionary transition from fish to four-legged animals (tetrapods). Tiktaalik lived around 375 million years ago, during the Devonian Period. It was able to use its fins to pull itself through shallow water, as well as propping itself up by doing “push-ups.”
Tiktaalik is an important transitional species that shows us how fish fins eventually evolved into legs. It has features common to fish (scales, fins, and gills) and amphibians (a neck, ear notches, a flat head, and flattened ribs that gave the torso strength). Most importantly, its fins have a special bone structure that lets them pivot to support the animal’s weight.