The Mammalia in the 10th edition of Systema Naturae forms one of six classes of animals in Carl Linnaeus's tenth reformed edition written in Latin.The following explanations are based on William Turton's translations who rearranged and corrected earlier editions published by Johann Friedrich Gmelin, Johan Christian Fabricius and Carl Ludwig Willdenow: Linnaeus divided the mammals based upon the number, situation, and structure of their teeth; mammals have the following characteristics: