Dentition and Diet: Teeth Reveal What a Hominid EatsWithin the family Hominidae, the shape and size of teeth match the diet, so a skull alone can tell us what a species ate.Herbivorous Hominids: Teeth Built for GrindingHerbivorous members such as gorillas eat tough, fibrous leaves and stems.Large, flat molars and premolarsBroad, ridged grinding surfaces crush plant material into digestible pieces.Thick enamel resists wear from abrasive vegetation.Small incisors, reduced caninesCanines are used mainly for display and dominance, not for tearing meat.Robust jaw and powerful chewing musclesWide jaws produce a strong side-to-side grinding motion.The jaw joint and muscle attachments are built to withstand repeated grinding forces.ExampleA gorilla's molars carry thick enamel and pronounced ridges suited to grinding leaves and stems.This lets it process gritty plant material while resisting wear over a lifetime.Omnivorous Hominids: Teeth Built for a Mixed DietOmnivorous members such as humans and chimpanzees eat both plants and animal matter.A mix of tooth typesSharper incisors and canines bite and tear soft flesh, though they are less blade-like than a carnivore's.Flatter molars grind plant material, as in herbivores.This mixed set lets one mouth handle a wide range of foods.Less robust jawsSofter foods such as fruit and cooked meat need less grinding force, so the jaw is smaller and lighter than a herbivore's.ExampleA human uses incisors and canines to bite into fruit or tear meat.The molars then grind grains or vegetables at the back of the mouth.Reading Fossil Teeth: Inferring the Diet of Extinct HominidsParanthropus robustusMassive jaws and very large, thick-enamelled molars point to a diet of hard, fibrous foods like roots and nuts.These teeth resemble a modern gorilla's, so this species was likely mostly herbivorous.Homo floresiensisSmaller teeth than Paranthropus robustus suggest a more varied diet.That mix of meat, fruit and other soft foods fits an omnivore.Theory of KnowledgeWhat are the limits of using teeth alone to work out an extinct species' diet?How could isotope analysis or fossilised food remains support the conclusion?Active recallHow do the molars of a herbivorous hominid differ from those of an omnivorous one?Why are canines reduced in herbivorous hominids like the gorilla?Why is a herbivore's jaw more robust than an omnivore's?What features of Paranthropus robustus point to a mostly herbivorous diet?
