Question

Chapter 11: The Early Hominins of the Pliocene 292 FIGURE 11.18 A afarensis, maxilla. Photo, D. L. France; cast FIGURE 11.19 A. afarensis, mandible. Photo, D. L. France; cast from Institute of Human Origins from Institute of Human Origins Using the criteria of ape and human dentition from previous chapters, analyze the dentition of A. afarensis (Figures 11.18 and 11.19). In what ways is the dentition apelike? In what ways is it humanlike? 2.

Answer 1

The dentition of A. afarensis was an intermediate between the apes and the humans.

Dentition looked more ape like was as follows

1. Jaws were relatively long ,broad and narrow.

2. The teeth were arranged in rows that were slightly apart at the back then that of the front.

3. The palatal arch was less. Improper formation of the palatal depth or arch.

4. The canine teeth were pointed who tearing food.

5. A gap ( known as diastema) seen in between incisor and canine of the upper jaw and space between the premolar and canine of the lower jaw.

6. The premolar teeth resemble the apes having only one cusp for chewing.

Dentition looked more human life was as follows

1. The front incisor teeth are quite wide.

2. The mandible is more of a u shaped resembling humans. The jaw and the molars behind are curved giving the u shape.

3. The canines were pointed and sharp then the other teeth.

4. There was minimal formation of palatal Arch.

5. The molars were moderate in size and were more like human type having 'Y -5' pattern, that is they had 5 cusps arranged giving a Y shape to the occlusal surface of the molars.