Jaws evolve
A gill arch is repurposed into a hinged mouth, and vertebrates stop being filter feeders.
- When
- Known to
- ± 10 million years
- Era
- Ordovician, Paleozoic
Molecular evidence places the origin of jawed vertebrates in the Late Ordovician, around 450 million years ago, though the oldest complete jawed fossils come from the early Silurian of China. Jaws transform vertebrates from passive suspension feeders into active predators able to seize, bite and process prey, opening ecological space that every subsequent vertebrate — fish, amphibian, reptile, mammal — occupies.