Final answer:
Vertebrates developed jaws in the Silurian period, moved onto land during the Devonian, and the first amniotes, which could reproduce on land, appeared in the Carboniferous period.
Step-by-step explanation:
Vertebrates evolved jaws in the Silurian period, then transitioned to land in the Devonian period, and the earliest amniotes are known from the Carboniferous period. The development of jaws was a significant advancement in early vertebrate evolution, allowing for more efficient feeding and predation. Amphibians, which were the first vertebrates to inhabit land, emerged from lobed-finned fish about 365 million years ago. However, they still needed to return to water to reproduce. In contrast, the earliest reptiles, which evolved from amphibians at least 300 million years ago, were the first vertebrates to reproduce on land due to the evolutionary milestone of amniotic eggs. These eggs allowed embryos to breathe without drying out, leading to the diversification and widespread colonization of terrestrial environments by amniotes, including reptiles, mammals, and birds.