Oct 25, 2018. The paucity of fossils from the time of the earliest vertebrates—around 480 million years ago—has made it hard to definitively determine the types of habitats where backbones first evolved.

When did vertebrates evolve?

Vertebrates appear to have radiated in the late Ordovician, about 450 million years ago. However, most Ordovician fossil fossil vertebrates are rare and fragmentary, although available material suggests that ancestors of the sharks and jawed fish were present along with various lineages of armored jawless fish.

What is the order of evolution for vertebrates?

Amphibians, reptiles, mammals, and birds evolved after fish. The first amphibians evolved from a lobe-finned fish ancestor about 365 million years ago. They were the first vertebrates to live on land, but they had to return to water to reproduce.