Fish fossils reveal new clues about the origin of vertebrate "hands"

BEIJING, March 24 (Xinhua Zhang Mengran) According to a study published in the British journal Nature on the 23rd, scientists found a fish fossil with finger-like appendixes on its pectoral fins, bringing new clues to understanding the origin of vertebrate hands. This is by far the most complete sample of the hope, representing the evolutionary phase of the transition from fish to land vertebrates, and the first time that fingers and fins have been found in known animal fossils, revealing how human hands evolved step by step from the fins of ancient fish.
bones suggest that the image of the quadreds appeared about 374 million years ago, but some older fossils contain limb-like bones that may suggest that the four-legged animals originated even earlier. Until then, the evolutionary record of vertebrates expanding to land has relied heavily on a small number of four-legged fossils from the mid-to-late mud basin (393 million to 359 million years ago). None of these fossils, however, reveals the complete bone structure of the pectoral fins.
researchers at the Rimusky Campus of the University of Quebec in Canada and Flinders University in Australia described the most complete fossil yet; the 1.57-meter-long fossil is from the Esquiminak formation in Quebec, Canada. Using high-energy computer-scanning technology, the team determined the bone structure of its pectoral fins and found two clearly identifiable fingers and three other presumed possible fingers, but the pectoral fins retained the fins.
Long, a professor of paleontological strategy at Flinders University, said the discovery of a complete specimen of a four-legged fish called the hope moth reveals extraordinary new information about the evolution of the hands of vertebrates. It is also the first time that scientists have "indisputably" found fingers and fins "locked" together in known animal fossils, simply by discovering a "transitional structure" that is evolving from fin to hand.
scientists have found that the so-called fins have joint parts, much like the finger bones on the hands of most animals today. They concluded that the bone structure was the most likely example of a four-legged animal found in a pectoral fin, and that the vertebrate's hand originated from the bone shape inside the boso fin.