The chosen statement will then lead either to the next pair of statements or to the final identification. Each pair of statements usually contains both cranial and external character traits, and all such traits should be examined for a positive identification. All identification keys are limited somewhat by the amount of morphological variation that exists in natural populations. The characters selected for this key and the range of variations used should be reliable for the recognition of most of the mammals of Oklahoma. Some species of suspected but unverified occurrence are included in the key.
Maps show the distribution of each species in the state of Oklahoma.
Counties in which a species has reported are highlighted in blue. Dental formulas are an easy way to indicate the number of each type of tooth for a species. The types of teeth are incisors, canines, premolars, and molars. If you already know the name of the animal you are looking for, click here to go to index of the animals contained within the key, indexed alphabetically by species.