The first vertebrates
Two small, finless, jawless swimmers in Chinese shale are the earliest known members of our own lineage.
- When
- Known to
- ± 2 million years
- Era
- Cambrian, Paleozoic
Myllokunmingia and Haikouichthys, both about 518 million years old and only a few centimetres long, show a head, paired eyes, gill pouches and a notochord with signs of rudimentary vertebrae. They are the oldest craniate-grade chordates known. Every fish, amphibian, reptile, bird and mammal — including every human — descends from animals of roughly this kind.