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An artist’s reconstruction of Qianodus duplicis, the earliest known fish that had a mouth with teeth Heming Zhang
Smithsonian Magazine has a post about some amazing fish fossils. A series of papers published in the journal Nature shed light on the evolution of teeth and jaws. The discovery of these fossil fish from the Silurian of China has pushed back the oldest jawed fish to about 436 million years ago. Previously, the oldest known jawed vertebrate was 425 million years ago. There are instructive twitter threads by Matt Friedman and Ron Sansom.
Our teeth and jaws are incredibly ancient. They’re older than dinosaurs, older than arms and legs, older than trees–adaptations that paleontologists have tracked to our distant, fishy relatives that thrived in the seas around 425 million years ago. But a trove of delicately-preserved vertebrates found in China has set a new date for the earliest record of jaws and teeth. The aquarium’s-worth of early vertebrates include some of the earliest fish with paired appendages, one of the earliest relatives of sharks, and, at about 436 million years old, the most ancient fossils yet found of fish with teeth and jaws.
Researchers have disagreed about exactly when the earliest bites evolved. Molecular studies based upon estimations of genetic changes have proposed that the first jaws and teeth evolved about 450 million years ago. Until now, the oldest fossils of jawed vertebrates–or gnathostomes –dated to about 425 million years ago, a significant gap. As Institute of Vertebrate Paleontology and Paleoanthropology researcher Min Zhu and colleagues describe in a series of Nature papers published today, the new finds from South China sit in the middle of this gap and offer a startling look at a critical moment in evolutionary history.
The Nature papers are:
