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.
Plesiadapiformes is an extinct order of mammals which is either closely related to primates or a precursor of them. They first appear in the fossil record between 65 and 55 million years ago. It is thought that these were the first mammals to have developed finger nails in place of claws. Based on fossil evidence, the earliest known true primates were represented by the genus Teilhardina date to 55.8 million years old. This was a marmoset like primate that lived about 56-47 million years ago. Archicebus is a genus of primate also from around 55 million years ago.