The oldest fossils that are usually assigned to Chaetodon date from the late Oligocene, about 25 million years ago.
But since it is not easy to distinguish this genus from close relatives, it may be that the Oligocene fossils are actually of other Chaetodontidae.
The fossil record of this family is scant indeed, only Chelmon (or some similar genus like Chelmonops or Coradion) being known from Miocene remains.
As even crude molecular clocks suggest that the ancestors of the Chaetodon and the Chelmops lineage diverged in the Late Eocene already, nothing more can be said without new fossils being discovered.
The oldest fossils that are usually assigned to Chaetodon date from the late Oligocene, about 25 million years ago. But since it is not easy to distinguish this genus from close relatives, it may be that the Oligocene fossils are actually of other Chaetodontidae. The fossil record of this family is scant indeed, only Chelmon (or some similar genus like Chelmonops or Coradion) being known from Miocene remains. As even crude molecular clocks suggest that the ancestors of the Chaetodon and the Chelmops lineage diverged in the Late Eocene already, nothing more can be said without new fossils being discovered.
Chaetodon