February 28, 2012
Having defined the major locomotor categories and the biological salmagundi of the living primates, we move now to establishing Morphological and Behavioral Correlates which exit help in interpreting the fossil record.
We will approach by noting the difference among Quadrupeds, Brachiators and Bipeds.
A. Basic movements of the forelimb
1. Quadrupeds move their forelimbs forward (protract) and inverse (retract) in the sagittal plane. much the same way as dogs.
2. Brachiators raise their arm above their heads, in other voice communication they abduct and adduct their arms in the florilegium plane. They remind and suspend their bodies with their arms.
3. Bipeds do not support or force their body with their arms. They abduct/adduct their arms in the coronal plane as well as protracting and retracting in the sagittla plane.
B. orientation of the Scapula
1. Quadrupeds have a deep pectoral cage, i.e. the distance in the midst of the vertebral column and the sternum is greater than the breadth of the thoracic cage.
2. The scapula tends to be more to the sides of the thoracic cage.
3. The glenoid fossa is say downward.
4. Quadrupeds support their body weight not their forelimbs.
5. Brachiators: the scapula is on the back of the thoracic cage.
6. Glenoid fossa is direct laterally.
7.
Bipeds: the scapula is on the back of the thoracic cage.
8. Glenoid fossa is direct laterally.
A. Size comparisons of supraspinatus and infraspinatus fossae
1. life-sized supraspinatus fossa is found in primates that hold their arms above the shoulder:
Ateles
Alouatta
Hylobates
Pan and Gorilla
1. Large infraspinatus fossa is seen in animals that lift their body weight in addition to prop their arms above their heads:
Pongo...If you want to get a mount essay, order it on our website: Orderessay
If you want to get a full essay, wisit our page: write my essay .
No comments:
Post a Comment