Conventional wisdom has it that the first creatures to emerge from the water eons ago did so without hind limbs. Conventional wisdom, meet Tiktaalik roseae. As the Boston Globe explains, Tiktaalik is a 375-million-year-old fish that swam in what is now the Canadian Arctic. Researchers already knew that the fish had front fins akin to limbs, but a new study of its large pelvis suggests that the creature had similar hind features, too. "The fins undoubtedly were employed as paddles to swim, but might also have been used in a leg-like way on occasions," observes the BBC.
The upshot from the study in the Proceedings of the National Academy of Sciences is that some creatures might have developed legs, or something very much like them, while still living in the water, reports LiveScience. “It’s what we’ve all been waiting for,” says a Cambridge paleontologist not involved with the study. "Until this discovery, we weren’t able to see the changes by which the pelvic fins of the fish became much larger and more robust, and gradually turned into the tetrapod hind limb.”