Next, we believe skull number four is Australopithecus afarensis. A. afarensis is about three to two million years old. This specimen has flat nasal bones and it doesn’t have a chin. The foramen magnum is also in between, which leads us to believe that this was not the common ancestor, but a link in between. This skull also has a fairly pronounced facial prognathism and a large facial slope of thirty degrees. This skull was more ape-like than human, which lead us to believe that it was one of the older skulls. Then, we believe skull number five is Homo erectus. H. erectus is about 1.39 million to 143,000 years old. This specimen had a fairly vertical face; the facial slope was only fifteen degrees and the facial prognathism was minor. It did not have a sagittal crest and its supraorbital brow ridge was small. Although the foramen magnum was in between and the nasal bones were flat, the underlying human-like traits and skull structure lead us to believe that this specimen was an ancestor of the modern day human. After that, we believe skull number six is Gorilla gorilla. G. gorilla is about twenty thousand years old. This skull has a very pronounced facial prognathism and its facial slope is thirty one degrees. The foramen magnum was towards the rear, which means that this specimen did not walk upright. The supraorbital brow ridge was very large and its nasal bones were flat as well. The skull also had a sagittal crest, the braincase measurements large, and the combined chewing surface was quite large, which leads us to believe that this is a modern gorilla. Next, we believe skull number seven is Australopithecus africanus. A. africanus is about 3.3 million to 2.1 million years old. This skull had a small supraorbital ridge and a sagittal crest. This skull is a little similar to A. afarensis, but slightly larger in brain size. This specimen also had the largest combined chewing surface of all the skulls and its nasal bones were in between. The forehead was horizontal and the facial slope was twenty three degrees. This skull also seemed more ape-like than human-like. Some the characteristics were in between, which lead us to believe that this skull had room for change, therefore becoming the common ancestor.
Lastly, we believe skull number eight is Homo Neanderthalensis. H. Neanderthalensis is believed to have originated about 200,000 years ago to 28,000 years ago. This skull had arched nasal bones and a centered foramen magnum, which immediately lead us to believe that this was an ancestor of the modern humans, because ape-like creatures do not have distinct arched nasal bones. The combined chewing surface was similar to the other human-like skulls as well and the facial prognathism was minor. This skull did not have a sagittal crest and there was not a canine diastema or jut. This skull seemed to have fit in the more human-like group of skulls, which lead us to believe that this was a Homo Neanderthalensis.
In conclusion, we believe we have figured out which skull is which by using distinctive characteristics. Over time, in the modern human perspective, we have noticed that arched nasal bones form and facial prognathism decreases. The foramen magnum is also centered, which allows us to walk upright. We also gradually develop chins and out canine just and diastema are not visible. Through the great ape route, their canine jut and diastema are far larger than their ancestors, and their facial prognathism has increased as well. We’ve learned that we’ve changed over time and we’re curious about how we’ll change to adapt to our environment in the future.