310mya Sauropsids (lizard-faced non-mammalian chordates)

REPTILES & BIRDS. 

The term reptile is not a true clade name, as it fails to include birds which share a common ancestry which are the only surviving speciments of dinosaurs which mostly went extinct 65mya.

Sauropsids are a diverse group of mostly egg-laying vertebrate animals. The Sauropsida includes all modern and most extinct " reptiles", but excludes synapsids (mammals). Living sauropsids include lizards, snakes, turtles, crocodiles, and birds. Extinct sauropsids include non-avian dinosaurs, pterosaurs, plesiosaurs, ichthyosaurs, and many others.

Between the lobe-finned fish tetrapods and the first amphibia and amniotes in the Middle Carboniferous lies a gap of 30 million years, with few satisfactory tetrapod fossils. This, noted in 1950, is Romer's Gap. Some new fossils were found in the 1990s, such as Pederpes, right in the middle of the Romer Gap. The gap still obscures the details of the tetrapod transition.

Sometime, in the later Devonian or earliest Carboniferous, the fishapods became mainly land-based. One group of them kept their link to the water, and always laid their eggs in water. They became the amphibians. The others evolved a way of laying eggs on land. They were the amniotes, whose key innovation was the cleidoic egg.

Sometime in the middle or lower Carboniferous, the amniotes split into two lines. One line lead to the reptiles of all kinds, and we call that the Sauropsida. The other line led eventually to the mammals, and we call that the Synapsida. It is not right to say "mammals evolved from reptiles" because both groups derived from early amniotes. In any event, modern reptiles are vastly different from modern mammals. Both groups have evolved for over 300 million years from the early amniotes.

One branch of dinosaur sauropsids that have survived are the avians and although there are many species of wild birds that enthral us with their plumage and song, an unfortunate jungle fowl was domesticated and bred to be the most abused bird on the planet for it's meat and eggs.  Today, billions of chickens are kept in vile conditions as egg laying machines or killed at 6-8 weeks of age, having been bred to put on weight at such an unnatural rate that it maims and kills them from lameness.