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.
Large reptiles were beginning to be replaced by mammals as the dominant large land animals. Among the mammals, there were a few archaic egg-layers like the ancestors of the platypus and echidna. There were larger numbers of pouched opossum-like mammals . The few placental mammals that existed at that time mainly consisted of the Insectivore ancestors of primates.