Wings appeared by the Late Carboniferous. First appeared Late Devonian Aquatic or semi-aquatic Eggs and young in water Broad spectrum of shapes, sizes, and modes of life. The key feature in the origin of reptiles is the development of the amniotic egg . Eliminated need to lay eggs in water, allowing vertebrates to live and reproduce on dry land for the first time. Amniotic egg probably evolved in Carboniferous.
General trends show a necessity to build the food chain.
Major climatic changes Glaciers spread over Gondwanaland then melted and retreated Drying of climates at low latitudes led to contraction of coal swamps and extinctions among spore-bearing plants and amphibians. Reptiles diversified and began to replace amphibians in various ecological roles. The skeletal anatomy is reptilian, but the skull resembles that of Seymouria , an amphibian. Many lived in swamps. Extinct at the end of the Permian.