When did Agnatha first appear in the fossil record?
Keeping this in view, when did the Agnatha first appear in the fossil record?
420 million years ago
Likewise, what era did the first fish appear? During the Cambrian period, the first fish-like creatures (although definitely not recognized as true fish by paleontologists) appeared, around 530 million years ago. The Pikaia, which looked more like a worm than a fish, is perhaps the earliest ancestor of fish.
Similarly, when did vertebrates appear in the fossil record?
450 million years ago
What were the first vertebrates to appear on land?
Amphibians were the first tetrapod vertebrates as well as the first vertebrates to live on land.