A group of ancient amphibians called temnospondyls evolved stiffer spinal columns to adapt to aquatic life, contrary to previous hypotheses, according to a study published June 9, 2021 in the open-access journal PLOS ONE by Aja Mia Carter of the University of Pennsylvania and colleagues.
JAMES KUETHER/SCIENCE PHOTO LIBRARY
One of the greatest transitions in evolutionary history was the emergence of tetrapods, or four-legged vertebrates, onto land. By about 340 million years ago, fins had become fingers and limbs, shoulder and hip joints had changed to bear weight on land, and an entire array of amphibious creatures had begun to live along the water’s edge. But an analysis of some early tetrapods now suggests that not long after they made a home on land, some species became adapted to life in the water all over again.
Aja Mia Carter at the University of Pennsylvania and colleagues focused on a group of early amphibians called temnospondyls, roughly salamander-like tetrapods that spun off a great diversity of species between 330 and 295 million years ago.