What kinds of fish are most ancient?

1 Answer
Oct 27, 2016

Oldest fish that evolved on earth were armoured fishes, now included in a fossil group named, Placodermi.

Explanation:

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Jawed vertebrates evolved in the form of armoured fishes, included now in an extinct group called Placodermi. These organisms evoved in Ordovician period, about 480 million years ago but all of them disappeared at the end of Devonian period.