Biology
215 Labs: Mammals and Evolution
During this lab you will
examine the skulls and skeletons of a variety of mammals. You will take
measurements of various processes and make conclusions as to the eating
and survival habits of these animals. Answer the questions below
and in the "For furhter thought..." section to better
prepare you for the laboratory session.
The following are terms you will need to understand in completing this lab. Define each.
- Sagittal Crest
- Coronoid Index
- Dental Formula (Used to determine the order of mammals)
Incisors (Front Teeth)
Canines (Conical and sharp)
Premolars (several points; small molars)
Molars (may also have several points; flat in herbivores)
Count the number of Incisors, Canines, Premolars and Molars on one side of the upper jaw--this is the top of the dental formula.
Count the number of Incisors, Canines, Premolars and Molars on one side of the lower jaw--this is the bottom of the dental formula.- Tooth Occlusion
- Zygomatic Arch
- Diastema--
In the skull to the left, the diastema is the large gap in between the incisors and the premolars. Note the absence of canines. Do you suppose this skull belongs to a carnivore or an herbivore?
What mammal is depicted in the picture to the right? Note the homodont dentition.
What basic differences do you see in the skull to the left? What type of animal do you suppose this skull is from?
For Further Thought....
Examine the external morphology of the two animals pictured below.
To what class does each belong?
How do you explain the external similarities?
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