Bare Bones and Skulls
drwhitey@comcast.net    Oak Ridge, TN
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IDENTIFYING MAMMAL SKULLS
 

Name

Dental Formula

 Other Diagnostic Features
Didelphis virginiana
Opossum		  I5/4 C1/1 P3/3 M4/4 = 50 Prominent crest. Broadly expanded nasal bone. Incurved angle of mandible.
Scalopus aquaticus 
Eastern Mole		  I3/2 C1/0 P3/3 M3/3 = 36 Weak zygomatic arch
Dasypus novemcinctus
Armadillo		   Peg-like teeth
Sylvilagus floridanus
Eastern Cottontail Rabbit		  I2/1 C0/0 P3/2 M3/3 = 28 Two pair of upper incisors. Long post-orbital process. Boney network above maxilla.
 Tamias striatus
Eastern Chipmunk		  I1/1 C0/0 P1/1 M3/3 = 20 Cheek tooth rows tend to converge. # of teeth.
Marmota monax
Woodchuck		  I1/1 C0/0 P2/1 M3/3 = 22 Flat upper surface in profile. Post-orbital process at right angle to skull. Depression between post-orbital processes.
Sciurus carolinensis
Eastern Gray Squirrel		  I1/1 C0/0 P2/1 M3/3 = 22 Skull length 2 3/8 - 2 1/2 inches
 Glaucomys volans 
Southern Flying Squirrel		  I1/1 C0/0 P2/1 M3/3 = 22 High arched dorsally
Castor canadensis
Beaver		  I1/1 C0/0 P1/1 M3/3 = 20 Size and number of teeth.
Erethizon dorsatum
Porcupine		  I1/1 C0/0 P1/1 M3/3 = 20  
Ondatra zibethicus 
Muskrat		  I1/1 C0/0 P0/0 M3/3 = 16 Gradual constriction between orbits. Prominent post-orbital process.
Canis latrans
Coyote		  I3/3 C1/1 P4/4 M2/3 = 42 Prominent occipital crest
Canis lupus 
Gray Wolf		  I3/3 C1/1 P4/4 M3/2 = 42 Large. Very prominent occipital crest
Vulpes vulpes
Red Fox		  I3/3 C1/1 P4/4 M2/3 = 42 Paired dorsal ridges converge. Shallow supra-orbital depression
Urocyon cinereoargenteus
Gray Fox		  I3/3 C1/1 P4/4 M2/3 = 42 U-shaped dorsal ridges. Deep supra-orbital depression
Ursus americanus 
Black Bear		  I3/3 C1/1 P4/4 M2/3 = 42 Hard palette extends beyond molars. Shaped like raccoon with different tooth number.
Procyon lotor Raccoon  I3/3 C1/1 P4/4 M2/2 = 40 Broad. Palette extends beyond molars. # of teeth.
Mustela vison
Mink		  I3/3 C1/1 P3/3 M1/2 = 34 Auditory bulla longer than wide. "Dumbbell-shaped" molar.
Lontra canadensis
River Otter		  I3/3 C1/1 P4/4 M1/2 = 38 Broad rostrum. Constriction between orbits.
Mephitis mephitis
Striped Skunk		  I3/3 C1/1 P3/3 M1/2 = 34 Palette not extended beyond molars. Molars with equal length & width.
Lynx rufus
Bobcat		  I3/3 C1/1 P2/2 M1/1 = 28 Rounded. # of teeth.
Odocoileus virginianus  
White-Tailed Deer		  I0/4 C0/0 P3/3 M3/3= 32 No upper incisors. Boney network above maxilla. Long coronoid process of the mandible.
Sus scrofa
Wild Boar		   Tusks. Very high occipital region, then slanting toward nasal region.