Reptiles are classified into four orders: crocodiles (Crocodylia), lizards and snakes (Squamata), turtles (Testudines) and tuataras (Sphenodontia). Of these four, the first three are represented in Mexico.
Of the 23 species of crocodiles in the world, four species have been recorded in Mexico: two crocodiles and two alligators.
Of the 381 recorded species of snakes in Mexico, most are colubrids (Colubridae).
Seven of the eight sea turtles of the world live and breed in Mexico. Kemp's Ridley (Lepidochelys kempi) only breeds in Mexico.