New principle of mammals guidebook

The checklist of mammal fauna of Karelia on the basis of the lower jaw (in the skeletons found in the nature, this part remains whole) was built. It does not consider any taxons except the lowest, specific. The structure of the checklist corresponds to balanced "binary tree". It incorporates the principle of equiprobable alternative sampling. The signs to characterize species are selected in such a way that at each step of determining each thesis and antithesis group would divide the group of two possible species into halves. Wherein the total number of steps equals to the binary logarithm of the number of species, i.e. to detect any kind of local flora is necessary only about six steps. The checklist results very compact and convenient in the field.