The Comparative Anatomy of Eating                                                                              by Milton R. Mills, M.D.

 

1 -Facial Muscles

2 - Jaw Type

3 - Jaw Joint Location

4 - Jaw Motion

Carnivore

Reduced to allow wide mouth gape

Angle not expanded

On same plane as molar teeth

Shearing; minimal side-to-side motion

Herbivore

Well-developed

Expanded angle

Above the plane of the molars

No shear; good side-to-side, front-to-back

Omnivore

Reduced

Angle not expanded

On same plane as molar teeth

Shearing; minimal side-to-side

Human

Well-developed

Expanded angle

Above the plane of the molars

No shear; good side-to-side, front-to-back

 

5 - Major Jaw Muscles

6 - Mouth Opening vs. Head Size

7 - Teeth (Incisors)

8 - Teeth (Canines)

Carnivore

Temporalis

Large

Short and pointed

Long, sharp and curved

Herbivore

Masseter and pterygoids

Small

Broad, flattened and spade shaped

Dull and short or long (for defense), or none

Omnivore

Temporalis

Large

Short and pointed

Long, sharp and curved

Human

Masseter and pterygoids

Small

Broad, flattened and spade shaped

Short and blunted

 

9 - Teeth (Molars)

10 - Chewing

11 - Saliva

12 - Stomach Type

Carnivore

Sharp, jagged and blade shaped

None; swallows food whole

No digestive enzymes

Simple

Herbivore

Flattened with cusps vs complex surface

Extensive chewing necessary

Carbohydrate digesting enzymes

Simple or multiple chambers

Omnivore

Sharp blades and/or flattened

Swallows food whole and/or simple crushing

No digestive enzymes

Simple

Human

Flattened with nodular cusps

Extensive chewing necessary

Carbohydrate digesting enzymes

Simple

 

13 - Stomach Acidity

14 - Stomach Capacity

15 - Length of Small Intestine

16 - Colon

Carnivore

Less than or equal to pH 1 with food in stomach

60% to 70% of total volume of digestive tract

3 to 6 times body length

Simple, short and smooth

Herbivore

pH 4 to 5 with food in stomach

Less than 30% of total volume of digestive tract

10 to more than 12 times body length

Long, complex; may be sacculated

Omnivore

Less than or equal to pH 1 with food in stomach

60% to 70% of total volume of digestive tract

4 to 6 times body length

Simple, short and smooth

Human

pH 4 to 5 with food in stomach

21% to 27% of total volume of digestive tract

10 to 11 times body length

Long, sacculated

 

17 - Liver

18 - Kidney

19 - Nails

 

Carnivore

Can detoxify vitamin A

Extremely concentrated urine

Sharp claws

 

Herbivore

Cannot detoxify vitamin A

Moderately concentrated urine

Flattened nails or blunt hooves

 

Omnivore

Can detoxify vitamin A

Extremely concentrated urine

Sharp claws

 

Human

Cannot detoxify vitamin A

Moderately concentrated urine

Flattened nails