Carnivores	Omnivores	Herbivores	Humans
	Facial muscles	Reduced	Reduced	Well-developed	Well-developed
	Jaw type	Angle not expanded	Angle not expanded	Expanded angle	Expanded angle
	Jaw joint location	On same plane as molar teeth	On same plane as molar teeth	Above the plane of the molars	Above the plane of the molars
	Jaw motion	No Side to side	no side	No shear; good side-to-side, front-to-back	No shear; good side-to-side, front-to-back
	Major jaw muscles	Temporalis	Temporalis	Masseter and ptergoids	Masseter and pterygoids
	Mouth opening vs. head size	Large	Large	Small	Small
	Teeth: Incisors	Short and pointed	Short and pointed	Broad, flattened and spade-shaped	Broad, flattened and spade-shaped
10	Teeth: Canines	Long, sharp, and curved	Long, sharp and curved	Dull and short or long (for defense), or none	Short and blunted
12	Chewing	None; swallows food whole	Swallows food whole and/or simple crushing	Extensive chewing necessary	Extensive chewing necessary
14	Saliva	No digestive enzymes	No digestive enzymes	Carbohydrate digesting enzymes	Carbohydrate digesting enzymes
16	Stomach type	Simple	Simple	Simple or multiple chambers	Simple
18	Stomach aciditywith food in stomach	≤ pH 1	≤ pH 1	pH 4-5	pH 4-5
20	Length of small intestine	3-6 times body length	4-6 times body length	10-12+ times body length	10-11 times body length*
22	Colon	Simple, short, and smooth	Simple, short, and smooth	Long, complex; may be sacculated	Long, sacculated
31	Liver	Can detoxify vitamin A	Can detoxify vitamin A	Cannot detoxify vitamin A	Cannot detoxify vitamin A
33	Kidney	Extremely concentrated urine	Extremely concentrated urine	Moderately concentrated urine	Moderately concentrated urine
35	Nails	Sharp claws	Sharp claws	Flattened nails or blunt hooves	Flattened nails
	Teeth: Molars	Sharp, jagged and blade-shaped	Sharp blades and/or flattened	Flattened with cusps vs. complex surface	Flattened with nodular cusps
	From The Comparative Anatomy of Eating, by Milton R. Mills, M.D. * "Body length" measured from neck to anus, as with the other animals
	The details are in Mills' paper.  The rest of this article covers mostly angles not in that paper.