The first identifiable placoderms appear in the fossil record during the late Llandovery epoch of the early Silurian; they began a dramatic decline during the Late Devonian extinctions, and the class was entirely extinct by the end of the Devonian.
The first identifiable placoderms appear in the fossil record during the late Llandovery epoch of the early Silurian. At the end of the Fammenian epoch, placoderms began a dramatic decline in species diversity during the Late Devonian extinctions, and the class was entirely extinct by the end of the Devonian.