Scientists have traced the origin of fingers and toes to fish-like creatures that roamed the seas 380 million years ago, according to a new study. The findings, published on Sunday in the British-based science journal Nature, upend the prevailing theory on the evolution of digits. It had long been assumed that the first creatures to develop primitive fingers were tetrapods, air-breathing animals that crawled from sea to land 10 to 20 million years later. The need to adapt to swampy marshlands and terra firma, the theory went, is what drove the gradual shift through natural selection from fish fins suitable only for swimming to weight-bearing limbs with articulated joints. The study reveals that rudimentary fingers were already present inside the fins of the s h a l l ow - water, Panderichthys, a transitional species that was more fish than tetrapod.