Question

What environmental changes occurred in the permian and mesozoic that favored animals with internal fertilization and amniotic eggs?

Answer 1

The superclass Tetrapoda contains the four-limbed vertebrates known as tetrapods ; it includes living and extinct amphibians, reptiles (including dinosaurs, and its subgroup birds) and mammals (including primates, and all hominid subgroups including humans), as well as earlier extinct groups. Tetrapods evolved from a group of animals known as the Tetrapodomorpha, who in turn evolved from ancient Sarcopterygii lobe-finned fishes around 390 million years ago in the middle Devonian period their forms were transitional between lobe-finned fishes and the four-limbed tetrapods.