What are Amniotes?
Amniotes are animals who shield the embryos of their offspring using extensive membranes or keeping them inside the body, in contrast to most other animals, which lay free-floating eggs in water. Amniotes include mammals, reptiles, birds, and the extinct mammal-like reptiles (theropsids) and dinosaurs. Of all 38 animal phyla, only one has amniote members — Chordata, and even then, many chordates, which include fish, sharks, rays, and amphibians, are not amniotes. All non-amphibian tetrapods are amniotes, however. Amniotes were nature’s way of making large land animals that were truly terrestrial in the sense that they did not depend on pools of water as a medium for reproduction. Land animals existed long before amniotes, but mostly as insects. The first amniotes resembled small lizards, and are variously stated as emerging between 350 and 310 million years ago, during the Carboniferous period. Instead of laying eggs with hard shells, they were surrounded by a tough membrane. These ear
