9.2 Skull Questions

Question 1

1. What differences do you notice about the brain case, jaws and teeth amongst the hominids and hominoids?

Answer 1

hominoids
-smaller brain case
-bigger + stronger jaws
-bigger teeth

Question 2

2. Gorillas have a very large sagittal crest. Why might this be?

Answer 2

This might be because jaw muscles are attached to this ridge that help with increased and stronger chewing

Question 3

What does the presence of the sagittal ridge of bone indicate?

Answer 3

It indicates that the organism has exceptionally strong jaw muscles

Question 4

3. The foramen magnum is located on the bottom of the skull. What does this indicate about these organisms?

Answer 4

-indicates the position of the spine in relation to the head
-therefore, indicates whether the creature was bipedal or moved about some other way
-also indicates when our ancestors developed the upright, bipedal posture

Question 5

4. Look at the position of the eyes. What advantage might binocular vision have for primates and especially, their tree travelling ancestors?

Answer 5

-allows the visual fields from both eyes to overlap, thus allowing three-dimensional vision and better depth perception
-useful for climbing trees, as you need to know how far the next branch is from your current position.
-also very useful in hunting other animals

Question 6

5. What shared derived characteristics do the skulls have?

Answer 6

(what makes us classify them together - similar/shared characteristics)

-forward facing eyes
-position of spine in foramen magnum

**these characteristics differ in size and/or shape due to different functions