In the fields of paleoanthropology and archaeology we are not just searching for bones of our early ancestors. Instead we are seeking knowledge of our biological and technological origins and how these characteristics have changed over time. Presently, the earliest fossil bipedal hominins are between 4- 7 million years old (discussed more in the next module) whereas the earliest evidence of stone tool use (based on cut marks on animal bones) is about 3.4 million years old. However, the oldest (published) stone tools uncovered are about 2.6-2.5 million years old and come from Gona, Ethiopia.
A working phylogeny of the australopithecines and Homo (after ref. 19). Flaked stone artifacts appeared at about the same time as the earliest species of Homo. The initial expansion of humans from Africa coincided roughly with the shift from the Oldowan to the Acheulean (handaxe) traditions. The subsequent expansion about 50,000 years ago coincided with the shift from the Middle Stone Age/Middle Paleolithic to the Later Stone Age/Upper Paleolithic traditions.
Figure from Richard G. Klein PNAS 2009, page 106
Questions that help us understand our evolution include:
- Why did Homo appear? When?
- What led Homo erectus (or H. habilis?) to expand outside of Africa?
- Who were the toolmakers? Where and How did they acquire the raw material? What was the purpose of each tool? Why was a particular location chosen by early toolmakers?
- What can be inferred about the behavior and/or culture of different hominin species?
In order to fully explore the past, a combination of researchers in paleontology, archaeology, and geology are needed to add a different piece of the ancient past.
Led by Dr. Harmand, field school students explored early stone artifact sites near the village of Nariokotome, West Turkana, Kenya. The Paleolithic (Early Stone Age) is divided into two technological categories called Oldowan and followed by Acheulean (see first figure above for timing). The following are pictures from our adventures.
DAY 1- We began our exploration at an Oldowan tool site called Lokalalei, containing approximately 2.3 million year old artifacts.
Students visit Lokalalei 2C, an excavated Oldowan site. After the excavation was complete, the dig site (beneath Dr. Harmand) was filled in with sediment.
Because we are new to archaeological surveying and may step on a possible artifact, we walk in a line behind Dr. Harmand.
After being shown a few Oldowan tools in the area, students are on their own to flag other stone artifacts. Approximately 2.3 million year old site of Oldowan stone tools.
Aileen finds a flake made of phonolite.
Page takes a water break after flagging a stone tool.
Larisa poses with a broken rock I found (not a stone tool).
Anna and Dylan find a basalt core.
On our way back to camp we stopped at the Turkana Boy Monument near the village of Nariokotome. This is where Dr. Richard Leakey’s team uncovered the fossilized remains of 1.6 million year old Homo erectus. How awesome to think we were standing in an area where an early hominin species once walked!! However, the paleo-landscape was very different from today. What type of tools did H. erectus create?
One of the first tourists to the Turkana Boy Monument in Nariokotome constructed by the Turkana Basin Institute. We were the first foreign tourists to this National Monument.
One of 3 plaques in front of the monument. The other two display the same text in Swahilli and in the local Turkana language.
In the Lowry…heading back to our campsite near the village of Nariokotome.
DAY 2- We saw an advancement in technology and differences in raw material at Kokiselei (approximately 1.76 million years old) with Acheulean artifacts.
On our way to the first of several Kokiselei sites with Acheulean artifacts. Again, we walk in line to make sure we don’t step on any artifacts or bones.
The survey area.
Anna finds a core.
Dr. Harmand explains the difference in tools they are looking at today from the previous day.
Mike poses with his find.
Page finds a flake!
Sam seems confused on what she is holding. Do you know what it is?
Page find another artifact!
Dr. Harmand describes the artifact to Larisa and the rest of the group.
Dylan doesn’t seem convinced that this was made by early hominins.
Dr. Harmand shows classic Acheulean tools such as this ax.
Making and Using Stone Tools
Part of our trip to Nariokotome involved acquiring raw material to make our own stone tools. We made two stops to collect the same type of material used in Turkana during the Early Stone Age- phonolite, basalt, and rhyolite
Part 1- Selecting raw material
Laga…search for phonolite.
Kate and Jayde- carrying their raw material.
Larisa is done selecting phonolite that she will use to make stone tools.
While students were looking in another area for rhyolite, I made sure to stop at these lacustrine stromatolite beds with TBI Field Assistant John (Ekusi).
More stromatolites! Anna for scale.
Rachel finds some rhyolite.
Jayde finds an even bigger piece of rhyolite for making stone tools.
This may not be the Geology module but we sure do have a lot of rocks! We chose specific types of igneous rocks that early stone tools in the region were made out of. It seems that the early hominins were selective in their raw material and kind of like early geologists! 🙂
Part 2- Knapping
Back at TBI-Turkwel, students worked on knapping. They began knapping quartz then moved on to material they collected near Nariokotome.
Our knapping area. Here we worked with quartz.
Tom did not like the bits that were hitting her.
Anna shows off her first tool made of quartz.
Dylan works on his first tool.
Larisa, Aileen, and Mike also attempt to knap quartz. There were many injured fingers during this activity. Ouch!
Page begins knapping a tool out of phonolite.
Jayde examines her phonolite flakes.
Larisa is using protective goggles…too many flying pieces. I wonder if early hominins lost an eye during this activity.
Mike cleans up the edge of his flake.
Aileen gets assistance from Dr. Harmand on how to strike the rock.
Rachel shows off her first strike.
Sam has made some sharp tools!
Rachel has good technique. Don’t strike straight down but strike at an angle.
Part 3- Using Stone Tools ***WARNING THE BELOW IMAGES ARE GRAPHIC OF A BUTCHERED GOAT****
It is highly likely that early stone tools were used in butchering animals. We don’t however know for sure if early hominins were hunters or scavengers but, researchers are able to distinguish between carnivore teeth marks on bones vs tool marks made at particular locations of a skeleton such as the tendons.
Below are a couple pictures of students putting their stone tools to use in the end of module Goat Roast.
Sam and Larisa show off their sharp tools they had just used. Sam’s tool is made of phonolite, Larisa’s tool is made of rhyolite.
Mike and Kate take their turn at using their tools.
Sam, Jayde, James, and Page take their turn at skinning the goat. Most agreed that their rhyolite tools were the sharpest and best at this type of work.
Now on to the next module and studying the evolution of our early ancestors….