A chemical formula contains information on the types and spatial arrangement of bonds in the chemical. It also tells you what elements are in the chemical, and how many atoms of each. The spatial arrangement is not necessarily very obvious from the formula, e.g. C2H5OH does not tell you much about the spatial arrangement of the bonds. A chemical formula contains information on the types and spatial arrangement of bonds in the chemical.
All modern amphibians are included in the subclass Lissamphibia, which is usually considered a clade, a group of species that have evolved from a common ancestor. The three modern orders are Anura (the frogs and toads), Caudata (or Urodela, the salamanders), and Gymnophiona (or Apoda, the caecilians).
Amphibians are vertebrate animals residing in a wide range of habitats, such as aquatic, terrestrial, and arboreal. Evolution of the earliest amphibians took place in the Devonian period; their features modified over a period of time. While some are extinct, following are the characteristics of the extant species of class Amphibia. Â» The color of the skin of amphibians is a result of three layers of cells called chromatophores. 1  Deepest layer is made up of melanophores. 2  Intermediate layer consists of guanophores giving the organism the blue-green color.  Topmost layer consists of lipophores, which give the yellow color to the organisms.