but goes back to the early evolution of tetrapods. In their paper published in the journal Biology Letters, the group describes their analysis of impressions on a stone slab made hundreds of ...

It was found very close to the shoulder girdle, and it has many of the features that are distinctive of early tetrapod lower jaws. What's really neat about it is it's a very skinny jaw -- it's ...

There's nothing magical about the number, yet five digits at the end of their limbs is a motif that runs through all the animals with four limbs, called tetrapods. Even when there are fewer than ...