A fire retardant is a substance that reduces flammability of fuels or delays their combustion. This includes chemical agents, but may also include substances that work by physical action, such as cooling the fuels, such as fire-fighting foams and fire-retardant gels.
These early mammals were small, insectivorous, nocturnal, hairy and warm-blooded. Warm-bloodedness is believed to have first evolved among the cynodonts, a late but successful group of mammal-like reptiles from which the mammals evolved.he Mammal-like Reptiles, or Therapsids first appeared about 285 million years ago near the begiining of the Permian which is well before the dinosaurs. They evolved quickly and many different groups arose.
Watch a salamander move, or even a crocodile: Its body twists from side to side with each step. Now compare to how a mammal walks. (Or a dinosaur, for that matter.) Instead of swinging their whole body side to side, the spine flexes up and down, and the legs swing directly forward and backward. OK, so marine mammals evolved from creatures specialized for walking, with spines that flex up and down but not side to side. That means that to transmit the force from their spine to the water, the tail needs to be horizontal, not vertical. Written Jun 29, 2014 â¢ View Upvotes â¢ Not for Reproduction.