"tiktaalik" lived about 375 million years ago. it is part of the transition between fish such as "panderichthys", known from fossils 380 million years old, and early tetrapods such as "acanthostega" and "ichthyostega", known from fossils about 365 million years old. its mixture of basal fish and derived tetrapod characteristics led one of its discoverers, neil shubin, to call "tiktaalik" a 'fishapod'.