The fish that walked—our ancestor's first steps onto land.

Tiktaalik is the "missing link" between fish and land animals, a perfect example of evolutionary transition. This 375-million-year-old fossil shows a creature with fish-like features—scales, gills, and fins—but also tetrapod characteristics like a mobile neck, robust ribs, and limb-like fins with wrist bones. The discovery of Tiktaalik in 2004 filled a crucial gap in the fossil record, showing how fish evolved the ability to walk on land. Its fins had the basic structure of tetrapod limbs, with bones equivalent to our upper arm, forearm, wrist, and fingers. The creature could likely prop itself up on its fins and move around in shallow water or on mudflats, hunting for prey. This transition from water to land was one of the most significant events in the history of life, opening up entirely new ecological niches and eventually leading to all land vertebrates, including humans. Tiktaalik's name comes from the Inuit word for "large freshwater fish," but it represents so much more—it's the fish that walked, the ancestor that made our existence possible. Every step we take on land is a continuation of the journey that Tiktaalik began 375 million years ago.