The document discusses several anatomical indicators that paleoanthropologists use to study skulls and determine aspects of an animal's biology, such as brain capacity, diet, and whether it was bipedal or quadrupedal. These indicators include the saggital crest, brow ridge, foramen magnum, eye position, occipital bun, zygomatic arch, jaw shape, chin, jaw robustness, teeth, muscle voids, and skull shape. Images are provided comparing human, gorilla, chimp, and dog skulls to demonstrate differences in these anatomical features.

1. Anth 100 Professor McKendricks

2. Skulls can show the brain capacity of the animal, dentition shows what the animal ate, and in some cases whether the animal is bipedal or not (McKendricks lecture). There are several indicators of all these factors that paleo-anthropologists look at.

3. The indicators are: a saggital crest, brow ridge, foramen magnum, how far eyes are from the head, occipital bun, zygomatic arch, shape of jaw, chin, robustness of jaw, dentition, any voids for muscle, tear drop shape skull due to temporal pinching, and catarrhine or platyrrhine faces.

4. Note the large saggital crest and the temporal pinching on the gorilla skull and the large occipital bun of the human skull. The saggital crest on top of the skull tells that there was some muscle on top of the skull which means that there was less room for the brain case. Tear drop shape of a skull due to temporal pinching means that there is again less room for the brain. The occipital bun shows that there is more room for the brain. http://www.gmilburn.ca/wp-content/uploads/2009/04/human_gorilla_skulls. (Top) http://www.daviddarling.info/images/human_skull_side. (Bottom)

5. Note the backward placing of the foramen magnum on the dog and chimp, but the center placing in the human. Note the sectoral scissoring of the gorilla’s teeth that are used to rip through shoots and other vegetation. The placing of the foramen magnum under the skull can show where the spine would go indicating if the animal was bipedal (located in center of skull) or not (located further back). Dentition shows if the teeth are specialized (good for ripping meat, etc.) or not (good for many things). http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/Foramen_magnum.jpg (Top) http://scienceblogs.com/afarensis/upload/2006/08/gorilla%203.jpg (Bottom)

6. Note the large zygomatic arch, very robust jaw, and the large area for muscle behind the head. The zygomatic arch, robustness of jaw, the brow ridge, and any voids for muscle all indicate how much muscle the animal has. http://www.a3bs.com/imagelibrary/VP762_1_L/zoology-models/VP762_1_L_gorilla-skull-gorilla-gorilla-male.jpg