When does the fossil record indicate that fish with jaws first appeared?
1 Answer
Feb 7, 2017
Fishes with jaw evolved may be 445 million years ago, in the Silurian period.They are grouped under Gnathostomata: gnathos meaning jaw.
Explanation:
The jawless vertebrates are called agnathans while jawed vertebrates are gnathostomatans. The first gnathostomata appeared in the form of fresh water armoured jawed fishes, as represented by fossils included in Placodermi.
Oldest placoderm fossils are found in Silurian deposits. They were abundant in Devonian but all became extinct about 360 million years ago.
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Timeline of events (gnathostomatans are pointed out and are the second from the left):
