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.
Amphibians are a group of tetrapod vertebrates that include modern-day frogs and toads, caecilians, and newts and salamanders. The first amphibians evolved from lobe-finned fishes approximately 370 million years ago during the Devonian Period.n this article, we'll take a look at six groups of amphibians, their characteristics and the organisms that belong to each group. Amphibians are one of the six basic animal groups. Other basic animal groups include birds, fish, invertebrates, mammals, and reptiles. Smooth Newt-Lissotriton vulgaris.