‘Exquisite’ Chinese fish fossils fill gaps in understanding the evolution of jaws in vertebrates
- Chinese team led by Zhu Min spent a decade hunting across China before discovering a crucial fossil depository in southern China’s Chongqing in late 2020
- Vertebrate palaeontologist John Long said the team’s discoveries rewrite ‘almost everything we know about the early history of jawed animal evolution’
New fish fossils from southwestern China have provided long sought-after evidence about the origin of jaws, one of the greatest innovations in the history of vertebrates.
For hundreds of millions of years, our planet’s most successful predators have used the same equipment – a set of powerful jaws – to capture and kill prey.
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Today, about 99.8 per cent of vertebrates, humans included, have jaws. A crocodile’s bite can be twice as powerful as a nail gun, enabling it to feed on large animals such as water buffalo.
However, how this innovation came about was unclear. While molecular studies led scientists to believe that jawed vertebrates first appeared 450 million years ago, an abundance of fossil records dates only as far back as 420 million years ago, leaving a critical 30-million-year gap in direct evidence showing what early jawed animals were like.
After a decade hunting at numerous sites across China, Zhu Min and his team from the Institute of Vertebrate Palaeontology and Paleoanthropology in Beijing discovered a fossil depository in Xiushan county in Chongqing in late 2020. It was dated back to the early Silurian period (439-436 million years ago).
“When we uncovered the complete jawed fishes in the laboratory from the rock matrix we brought back from Chongqing, our jaws were on the floor,” Zhu said. “We had never dreamed of finding such diversified, complete and exquisite jawed vertebrates from the early Silurian.”