Paleontologists in China uncovered a 419-million-year-old fish fossil with the earliest known version of modern jaw and facial bones. The find is standing one evolutionary view on its head.
Brian Choo/Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology
The next time you and a child make fish faces at each other, take a moment to appreciate Entelognathus primordialis's contribution to the giggles.
Paleontologists working in China have uncovered 419-million-year-old fossil remains of a fish they've dubbed E. primordialis, which sports the earliest known structures comparable to the modern jaw and facial bones in today's vertebrates, including humans.
The discovery "really is significant in helping to clarify this weird transformation – the evolution of faces," says Thomas Holtz Jr., a paleontologist at the University of Maryland at College Park.
A team led by Min Zhu, with the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, uncovered the remarkable preserved fossil in rock formations at a reservoir in Yunnan Province.
The fossilized fish, roughly 8 inches long, is complete, with bones still joined. Its head and shoulders are covered with bony plates, in addition to sporting a bony skeleton.
Finding an intact fish of any sort from this geological period, known as the Silurian, is rare enough, researchers say. To find one with such important clues to the evolution of faces is remarkable. The facial structure E. primordialis displays is sufficiently advanced to suggest that the origins of jaws and other facial bones among vertebrates originate even deeper in geologic time.
It's like finding pieces of a spacecraft amid the wreckage of medieval horse-drawn carts, says Xaiobo Yu, a paleontologist at Kean University un Union, N.J., and a member of the team reporting its results in Thursday's issue of the journal Nature.
Back in E. primordialis's day, Earth was undergoing gradual but remarkable changes. The south polar supercontinent Pangea was breaking up. What is now North America was isolated, wandering north as plate tectonics reshuffled the planet's land masses. Asia, and China in particular, were clusters of smaller land masses.