Grey wolves have long embodied the spirit of the wilderness. Once they had the largest natural distribution of any mammal except humans. Sadly, they can no longer claim this record as they have been lost from much of their former lands. Grey wolves still occupy a range of habitats including Arctic tundra, prairies and forests.
Although melanin is found in the skin of many species, in the reptiles, the amphibians, and fish, the epidermis is often relatively colourless. Instead, the colour of the skin is largely due to chromatophores in the dermis, which, in addition to melanin, may contain guanine or carotenoid pigments.kin of a different nature exists in amphibians, reptiles, and birds. All mammals have some hair on their skin, even marine mammals which appear to be hairless. The skin interfaces with the environment and is the first line of defense from external factors.
Reptiles Reptiles are essentially amphibians that are better adapted to life on land. Worldwide, there are ~7000 species in 4 orders.The arrangement of legs supports the reptilesâ body weight more effectively than amphibians, allowing them to have bigger bodies and to run.The wet skin that is characteristic of amphibians has been covered by dry scales and the eggs are encased in a shell to minimize water loss.mphibians Amphibians are direct descendants of fishes. They have damp skin like fish and most lay eggs lacking shells in water. Unlike fish, amphibians lack scales and have a more complex circulatory system. Most are terrestrial at some point in the life cycle.