Question

the first land vertebrates the amphibians developed during the which period​

Answer 1

By the late Devonian, 360 million years ago, early cartilaginous fish and bonyfish were diversifying. The late Devonian also marked the firsttetrapods -- vertebrates with true legs that could walk on land. By about 330 million years ago, in the Mississippian, several groups of land-dwelling amphibians had appeared.