What was the backbone of early tetrapods, the earliest four-legged animals, like?
High-energy X-rays and a new data extraction protocol have allowed researchers to reconstruct the backbones of the 360 million year old fossils in exceptional detail. The results shed new light on how the first vertebrates moved from water onto land.
Tetrapods are four-limbed vertebrates,today represented by amphibians, reptiles, birds and mammals. Around 400 million years ago, early tetrapods were the first vertebrates to make short excursions into shallower waters where they used their four limbs for moving around. How this happened and how they then transferred to land is the science debate.