Key to Regional Shrews


1. Total number of teeth less than 32; maxillary unicuspids less than 5: 2

1'. Total number of teeth 32; 5 maxillary unicuspids: (Sorex) 3

2. Total number of teeth, 28; 3 unicuspids in each maxillary tooth-row: Notiosorex crawfordi.

2'. Total teeth, 30; 4 unicuspids in each maxillary tooth-row: Cryptotis parva.

3.Third and fourth unicuspids approximately equal in size: 4

3'. Third unicuspid obviously smaller than the fourth: 6

4. Each upper unicuspid tooth provided with a pigmented ridge running from apex of tooth lingually to the medial cingulum of tooth, and there ending in a small pigmented cusplet: 5

4'. Each upper unicuspid without lingually directed pigmented ridge or medial cusplet; unicuspids crowded, narrow (from front to back), appearing high-crowned; underparts whitish: 8

5. Condylobasal length greater than 14.7 mm: Sorex cinereus.

5'. Condylobasal length less than or equal to 14.7 mm: Sorex preblei

6. Condylobasal length 20 mm or more; hindfoot fringed with stiff hairs; blackish above, white below: Sorex palustris.

6'. Condylobasal length 18 mm or less; hindfoot without fringe of stiff hairs; grayish or brownish above, tan or gray below: 7

7. Condylobasal length less than 15 mm; total length usually less than 100 mm; hindfoot 11 mm or less: Sorex nanus.

7'. Condylobasal length more than 15 mm; total length more than 100 mm; hindfoot 12 mm or more: Sorex monticolus.

8. Each upper front incisor with a small medial tine: Sorex arizonae.

8'. Upper incisor without medial tines: Sorex merriami.

Key slightly modified from Findley et al. (1975).


Last Update: 27 Jan 2008