This assignment fulfills two roles in this course: as a written paper and your final exam.
You Found A Fossil!
The year is 2021. You are a paleoanthropological graduate student working in east Africa. While excavating the Kibish Formation near the Omo River you and your team discover over two-hundred fossilized bones representing as many as 20 individuals. The fossil remains include both adult males, females and juveniles. The sediments date to between 2.8-3 million years old. Your first assessment suggests they could be possible human ancestors (hominins).
Osteological Data:
Skull
- Centralized foramen magnum
- Brain size is around 600 cubic centimeters
- Face is prognathic (compared to humans but much less when compared to apes)
Dentition (Teeth):
- Mandible and maxilla
- teeth show apical and occlusal (grinding) wear
- jaws lack diastemas
- jaws show medium-small canines
- large flat molars with rounded cusps but only 50% larger than a modern humans
- thick enamel
- The teeth show
- a microscopic wear pattern of light scratching
Post-cranial (below the skull) characteristics:
- The skeletons show
- arms slightly longer than their legs
- hands have small slightly curved phalanges
- Pelvis is bowl-like
- It has a short robust ilium that curves front to back
- It has a short robust ischium
- Femur with
- a long femoral neck
- bicondylar angle
- obturator externus groove
- It has a robust tibia
- Foot with
- a convergent toe
- Foot with
- The male skeletons are approximately 20 percent larger than the female skeletons.
Paleo-environmental Data
- Analysis of the fossilized pollen you collected from your site suggests the environment these fossils lived in consisted of pockets of wooded areas, interspersed throughout a very large, open grassy landscape. There are many predators including lions, hyenas, snakes, birds and even large bodied primates. The wooded areas offered a variety of trees and shrubs that appeal to a range of insects, birds and small mammals as well as fruits, grasses leaves and roots.
Stable Isotope Data
· Stable isotope data from the teeth shows a C4 signature.
Cultural Data
- Located at the same site, you also found some rocks
- Some are thick, pebble-like with battered, sharp edges
- Some are thinner, with sharp edges
- Others are round stones that fit in the hand but have evidence of percussion marks (small scars on the rock)
- The rocks are not uniform. They vary in size and shape.
- Near the rocks you found some highly fractured animal bones. You find a lot of
- leg bones
- skulls
- Under a microscope you see that the animal leg and skull bones show
- long abrasions
- some of the abrasions have a V-shaped shape to them
- on top of many of the V-shaped abrasions, there are abrasions with sides that are parallel to each other.
