Lesson Plan

Horse Teeth and Diet

3d replica of a horse jaw
Grade Level:
Upper Elementary: Third Grade through Fifth Grade
Subject:
Science
Lesson Duration:
90 Minutes
Thinking Skills:
Understanding: Understand the main idea of material heard, viewed, or read. Interpret or summarize the ideas in own words. Applying: Apply an abstract idea in a concrete situation to solve a problem or relate it to a prior experience. Analyzing: Break down a concept or idea into parts and show the relationships among the parts. Evaluating: Make informed judgements about the value of ideas or materials. Use standards and criteria to support opinions and views.

Essential Question

What can tooth morphology tell us about a horse?

Objective

Students will use the scientific method to learn about horse teeth morphology.

Background

Horses generally have between 36-44 teeth, all shaped for different purposes. Horses are primarily herbivores, meaning they eat plants. They can graze for up to 15-17 hours a day. Horses' incisors (and canines, in male horses) cut plants. Their premolars and molars grind the food before it is swallowed. 

Over time, eating plants leaves wear patterns on horses' teeth. Grazing continually grinds down the teeth. Over a horse's lifetime, teeth continue to erupt from their jaws to stay at the same height, until no tooth is left. If the animal lives to an old age, the remains of the tooth fall out.

Because diet and tooth wear are directly correlated, scientists (such as archeologists, biologists, and zoologists) can tell a lot about a horse's diet and lifestyle just by looking at their teeth. They can learn about the kinds of plants available, the age of the animal, sex, overall health, and other characteristics. This information helps scientists to understand the ecosystems in which horses lived with people at various points in time.

The 3d models of teeth from the Assateague Island horses should be referenced throughout this lesson.

Preparation

Gather snacks of various textures, such as raisins, baby carrots and crackers. Make sure that the snacks meet your school's rules.

Print a copy of "Mammal Teeth" for each student.

Write the list of vocabulary words (but not the definitions) on the blackboard. 

Use a classroom computer and projector to navigate to the Assateague Island 3d replicas on Sketchfab. Alternatively, download each skull and tooth file and take to a print shop, library, or maker's space to print multiple copies using a 3d printer.

Be sure to refer students to the 3d models throughout the lesson.

Materials

Lesson Hook/Preview

Hand out snacks of different textures (ex: chewy raisins, crunchy crackers, snappy baby carrots) to students.

Have the students munch one snack at a time. Ask them to observe which teeth they use to eat the snack, and what those teeth do. What type of snack did their molars help to eat? Which snacks used different teeth at different point of chewing? Students should share their observations with the class.

Explain that teeth are one of the most identifiable parts of a skeleton. When archeologists, biologists, or zoologists find teeth, they can observe them to learn about what their owner ate and how they lived.

Procedure

  1. Complete Lesson Hook activity.
  2. Introduce the scientific method. Show students the 3d replicas on the classroom screen or their individual computers, or distribute the print versions. Break students into five teams. Assign each team a step in the scientific method. Tell each team to be ready to address their step and record the answers.
  3. Take students through Step 1 of the scientific method: Make an observation & ask a question. Team 1 should identify questions that the teeth may answer, such as What does this horse eat? What is its age? Is it male or female?
  4. Take students through Step 2 of the scientific method: Gather information. Team 2 should identify sources of information or data to answer Team 1's questions. Answers might include: Read about horse skulls and teeth; Observe horse teeth; Compare horse teeth from different places. 
  5. Pass out the activity, "Mammal Teeth." Explain that students will gather information about horses' teeth by coloring in the drawings. Review the information about teeth, and write definitions for the vocabulary words on the blackboard.
  6. Take students through Step 3 of the scientific method: Form a Hypothesis . Ask Team 3 to reflect on the answers from Step 1 and Step 2. Ask the team to define "hypothesis" and provide three hypotheses about horses, teeth, and diets. (Examples: If this horse has a canine, then it is male. If this horse has long and angled incisors, then it is an adult horse. If this horse has many molars, then it uses them to graze grass. Note that students will have a clue about the sex of the horse from the activity labels.)
  7. Take students through Step 4 of the scientific method: Test the Hypothesis. Have students refer to the 3d replicas. Ask them to talk with each other about the horse’s diet and lifestyle and if their hypothesis can be tested with the information from the coloring pages. Ask students to compare results with each other as a way to test their hypothesis. At this point, students should know that their horse is an adult male who grinds its molars side to side to eat grass!    
  8. Take students through Step  5 of the scientific method: Share Results. Complete the assessment for the activity by completing the assessment - a bar graph.

Vocabulary

  • Adaptation: A change or the process of change by which an organism or species becomes better suited to its environment.  
  • Canines: The teeth behind the incisors on the cheek side of the mouth. They are cone-shaped and may even be dagger-like. They are used for seizing, piercing, and tearing. 
  • Carnivore: An animal that eats meat   
  • Herbivore: An animal that eats plants
  • Incisors: The flat, chisel-shaped teeth at the front of the mouth used in biting, cutting, nibbling, and stripping
  • Molars: The teeth located in the back of the mouth on the cheek side that have many major cusps (points) and are located in the back of the mouth. Molars function in grinding and crushing.
  • Morphology: The branch of biology that deals with the form of animals, plants, and any other living organism. It studies the structure of living organisms. 
  • Omnivore: An animal that eats both plants and meat  
  • Premolars: Transitional teeth located between the canines and the molars at the rear. They have one or more cusps (points) and are generally used for grinding and crushing, but they may also slice food. 

Assessment Materials

Share Results with a Bar Graph

Students will apply their knowledge of the scientific method and horse teeth identification by creating a bar graph to share their results.

We now know the horse is an adult male who eats grass and uses its molars side to side to eat grass. But how can we share data about the uniqueness of horse teeth? 

Use the coloring pages to count the number of each of the three types of teeth. List each type of teeth, and the number of each type. Use the data to create a bar graph.

A bar graph is a graphical display of data using bars of different heights. Each height represents a piece of information. Bar graphs can be used to compare items and values. It’s an easy way to visualize data and results. 

  • First, set up the graph. Draw a big “L” shape with enough room to add information. Based on what you’ve learned about horse teeth, what will your graph represent?
  • Second, label the axes. The horizontal axis is the side-to-side part of the “L” shape. It’s known as the “x” or horizontal axis. The vertical axis runs is the up-down part of the “L” shape. It’s called the “y” or vertical axis. Think about the scale: If you number the graph from 1-10, how clear is the information as opposed to numbering the graph from 1-20? (Note to teachers: The x axis should be labeled “Types of Teeth” and have spaces for three bars to show canines, incisors, and molars. The y axis should be labeled “Number of Teeth” and have a scale of 1-25.)
  • Third, name the bar graph. What is a descriptive title for the information to be presented?
  • Fourth, decide what information to graph on the x axis and the y axis. Refer back to the coloring pages.  
  • Fifth, fill in the types of teeth and color in the height of each which corresponds to the amount of teeth the horse has. 

Rubric/Answer Key

The bar graph should include incisors, molars, and canines. Bar heights are: incisors - 12, molars - 24, canines - 4.

Contact Information

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Tags: archeology archaeology biology horses zoology tooth morphology 3d printing

Last updated: March 4, 2021