Back in 2019，three Chinese scientists were playfighting during a break from working in the Chongqing Province，China. One was kung-fu kicked into a rock , causing an opening in the rockface. Inside，a wonderful fossil(化石) lay undisturbed，preserved for millions of years.
The fossil was a jawed fish，some 439 million years old，and the findings from the Chongqing site，along with other fossil findings in nearby Guizhou province，have excited the science world，as they are 11 million years older than any fish fossil found before. It is a significant discovery because scientists have suspected that jaws evolved(进化) some 450 million years ago, but there had yet tobe any fossils that supported this theory. The oldest fossils with jaws found were 439 million years old.
In this discovery，though，there was a new species of shark that was 439 million years old，with a full jaw.
"All these things are still like dreams, "said Zhu Min, who led the research teams that recently published four papers on the discoveries. "Today we are staring at complete early fishes，11 million years earlier than the previous oldest finds. These are both the most exciting as well as the most challenging fossils I have had the privilege to work on. "
Some of the fish that were discovered were placoderms，an extinct class of fish that have hard plates that formed a shield around the head and trunk，while others were an ancient type of shark.
The scientists found the oldest-known teeth of any vertebrate(脊椎动物)，14 million years older than any previous findings，as well as two other shark descendants. China has been the site of numerous discoveries in recent years，including fossils of feathered dinosaurs，as well as the oldest known animals on Earth.
"The discovery of the Chongqing site is indeed an unbelievable miracle of fossil hunting, "Zhuadded. "Suddenly we realized we have found a jaw-dropping fossil site. We are now close to the core of solving the fishy tree of early jawed vertebrates. "
