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).
Some of these trace fossils are as wide as four inches. Perhaps these animals did not actually breathe air, and only slimed along on land for short periods as a way of moving from pond to pond. According to scientific consensus, the first verified land animal was a one-centimeter myriapod. Present-day examples of myriapods include millipedes and centipedes. This myriapod, discovered in 2003 in Scotland and named Pneumodesmus newmani, is dated to 428 million years ago.