DINOSAUR PALEOECOLOGY:
DETERMINING THE DIET OF ANCIENT ANIMALS

David J. Davies
Department of Geology and Geography
Centenary College of Louisiana
Shreveport, LA 71104


Level: Upper elementary to senior high

 

Anticipated Learning Outcomes

Materials

Inexpensive, life-like models of dinosaur teeth, toe bones and other bones may be purchased from Dino Productions (P.O. Box 3004, Englewood, CO 80155-3004; (303) 741-1587) among other sources. They also include descriptions of the animals, a drawing of the tooth/bone for student handouts, and information on their life habits. They can assist you in determining the feeding habits of the animals whose "bones" you purchase.

Procedure

  1. Explain to the class the concept of "Functional Morphology" (Dodd and Stanton, 1990; Raup and Stanley, 1971); that is, animals have the shape they do because of their lifestyle. For example, the reason that predatory sharks have such a shape is they must be streamlined to catch prey. Birds, in order to fly, must have lightweight but strong, long wing bones. The same principle, popularly described as "function defines form", is also true for individual parts of the body; each part has a shape well adapted to its purpose. For example, since teeth are used to grasp and cut food, the tooth's shape must be effective in catching and chewing the type of food that the animal eats. Paleontologists determine the best model from the real world to use as an analogy for the body part. For example, the best machine to cut wood is a saw. Therefore, you would expect the jaw of an animal that eats hard, woody plants to have a battery of teeth in it that could cut like a saw.
  2. Then explain that dinosaurs and other large Mesozoic (Age of Reptiles, 245 to 65 million years ago) animals interacted with each other and their environment; the study of how organisms interacted with other species is called paleosynecology. All of these animals ate one of four types of food: meat (eaten by carnivores); fishes (piscivores); woody land vegetation (uplands herbivores); or soft swamp vegetation (bottomlands herbivores). Each must be processed differently to gain the maximum food value in digestion:
  3. Then demonstrate these four types of dinosaur feeding patterns by using the tooth models to grasp and process the imitation models of the appropriate food as a dinosaur would. For example, use the saw to cut up the small leafy branch, as an herbivore would have used its battery of teeth to cut up ancient uplands plants. Examples are listed below.

     Food Food Processor Model
     Meat Piercing, slashing, and cutting teeth  Pointed knife
     Fish Pointed teeth curved toward the back of the mouth to grasp and hold slippery prey  Fish gig
     Uplands (woody) vegetation Battery of short, sharp, serrated cutting teeth  Saw blade
     Swampy (soft) vegetation Battery of short, flat teeth for grinding soft food  Coarse sandpaper

  4. Groups of 3-4 students will then describe teeth from several different feeding types (guilds) of dinosaurs. Have the group discuss each tooth to determine: (a) the animal's diet; (b) the likely shape of each animal. These shapes may include bulky lowlands herbivore (hadrosaur); trim and fast running carnivore (Tyrannosaurus); water dwelling piscivore (ichthyosaur); uplands herbivore with long neck to reach tree tops (Apatosaurus or Diplodocus).

 

Results, Discussion, Conclusions

  1. Student groups, after working together, will determine from a single tooth the likely food source and overall body shape for each animal. They will write their responses in the table provided, and orally present their results to the class.
  2. Results will be checked by the teacher. Class discussion will then be initiated by naming the animal whose tooth was described, then showing color pictures of reconstructions of the dinosaur, its habitat and environment from library books on dinosaurs. Other aspects of its activities, e.g., family life, solitary or herd lifestyle, cold vs. warm blooded, and the techniques scientists use to determine these, can then be discussed to initiate further investigation into paleobiology.
  3. Discussion will follow centered on how each dinosaur was able to develop teeth so well suited to its particular lifestyle; this will lead to the students discovering the concept of adaptation and "survival of the fittest."
  4. This exercise allows dinosaurs, kid's favorite fossils, to be used to introduce basic topics of paleobiology such as predator/prey interactions; scientific methods of determining lifestyles of extinct animals; and processes of evolution.

Related Activity

A similar procedure to determine food source, animal body shape, weight and speed can be developed using toe or claw bones (bones used to obtain the food cut up by the teeth in the previous exercise). Are the toes light-weight, with slashing claw attachments as would come from a fast running carnivore (lion or Tyrannosaurus or Velociraptor); blocky to support much weight, like a bulky, heavy herbivore (elephant or Triceratops; or part of a paddle, as a swimming ichthyosaur would have?

References

DODD, J. Robert, and STANTON, R.J., Jr., 1990, Paleoecology: Concepts and Applications: Second Edition, John Wiley and Sons, 497 p.

Natural History Museum of Los Angeles County, 1987, Dinosaurs Past and Present: v. 1 and 2, University of Washington Press.

RAUP, David M., and STANLEY, Steven M., 1971, Principles of Paleontology: W.H. Freeman, 481 p.



WHAT DID THAT ANCIENT ANIMAL EAT?

NAME: __________________________

 Tooth Tooth Type Food Animal Shape Habitat
1        
 2        
 3        
 4        
 5        
 6        
 7        
 8        


 Toe Toe Type Food Animal Shape Habitat
A        
 B        
 C        
 D        
 E        
 F        
 G        
 H        

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