Tiktaalik fossils reveal how fish evolved into four-legged land animals
The fossilised remains of an ancient beast have revealed how prehistoric life hauled itself from the water and took its first unsteady steps along the path that led to four-legged land animals.
Clues to the seminal moment in the history of life were found in the bones of Tiktaalik, a 375m-year-old freshwater creature that grew to three metres long and had aquatic features mixed with others more suited to life on land.
Scientists first discovered Tiktaalik in 2004 while hunting fossils on Ellesmere Island in the Canadian Arctic. Its extraordinary blend of gills, scales, fins and lungs, combined with a movable neck, sturdy ribcage and crocodile-like head, placed Tiktaalik half way between fish and the earliest four-legged land animals.
| Illustration: Kalliopi Monoyios