USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Key to the Skulls of North Dakota Mammals

Key to Orders


1. Upper incisors absent (Fig. 1)....................................ARTIODACTYLA
   Upper incisors present (Fig. 2)..............................................2

2. Five upper incisors on each side.....................MARSUPIALIA (Didelphidae)
                                                             Didelphis virginiana
                                                                 Virginia Opossum
   Less than five upper incisors on each side...................................3

3. Diastema between incisors and molariform teeth, canine absent (Fig. 3).......4
   Diastema absent..............................................................5

4. Two pairs of upper incisors (second pair behind first pair and 
     much smaller)(Fig. 4).................................LAGOMORPHA (Leporidae)
   One pair of upper incisors............................................RODENTIA

5. Upper incisors of right and left sides separated by a space (a deep anterior
     emargination of the palate)(Fig. 5)............CHIROPTERA (Vespertilionidae)
   Upper incisors of both sides in a continuous row (no space)(Fig. 6)..........6

6. Canines prominent, longer than premolars or incisors (Fig. 2)........CARNIVORA
   Canines not well developed, seldom longer than premolars or
     incisors (Fig. 7)....................................INSECTIVORA (Soricidae)

Return to Contents
Next Section -- Note on Peromyscus

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/mammals/skulls/key.htm
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 05:57:25 EST
Sioux Falls, SD [sdww55]