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Finding fossils the traditional way

 

Finding fossils and other geological features is best done with a trained eye and on foot, where you can bend down and look more closely at your discovery and possibly pick it up and look at it from a different angle. For many year of fieldwork at Lake Turkana, trained fossil hunters have camped in the fossil areas and go out on daily prospection missions, walking over the landscapes looking for fragments that they identify and document on the surface. 

The team walk across the fossil exposures looking for fossil fragments on the surface.
The team walk across the fossil exposures looking for fossil fragments on the surface.
Fossil hunter bending down to inspect a piece on the surface. Photo Credit: Mike Hettwer
Fossil hunter bending down to inspect a piece on the surface. Photo Credit: Mike Hettwer

The team walk over the fossil exposures looking for fossil fragments and geological indicators, similar to the way that you can search for identifiable objects in the images on fOssilfinder. The fossil hunters have the added advantage of being able to pick up a specimen and turn it over to get a better look at it which can be most helpful in its identification. If a specimen is collected then it is essential that its exact position is recorded. Fossils should not be moved out of context.

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These coloured tracks on the Google image, mark the ground covered by the team over one week. These tracks are a useful indication of which areas need to be further covered.

When a discovery is made by a member of the team, a GPS position is taken as well as a digital photograph and some basic notes about the find. It is also given a unique field number, which is written on the fossil and on a small stone beside this so that the number is visible in the photograph for the database. You find many fossil fragments and artifacts on the surface, some of which are taken out of context as they are found in a dry stream bed or have been eroded out of sediments from above that have since washed away. It could therefore be a younger age than that of the deposits that it is sitting on. Ideally we want to discover a fossil that is in its original context and excavate this carefully to recover it.

This is an image of the excavation of a large and complete elephant skull.
This is an image of the excavation of a large and complete elephant skull.

This discovery of an elephant skull was made by spotting the teeth that were visible on the surface but after excavation the enormous skull was exposed. This was eventually jacketed in Plaster of Paris and lifted safely into the back of a car. You can see a video of this here

Once an important discovery is made, it is collected by the team, following strict procedures. Detailed notes are made about the surrounding sediment and rocks. We are interested to know if there are any nearby sandstones, what texture these sandstones are (coarse grained, fine grained, laminated, bioturbated etc.). We also document the presence of root-casts, rhizoliths, calcrete and quartz pebbles. These are good indicators of palaeoenvironment. We are interested in the presence of snails, fragments of fossil turtle, fish or crocodile, and also the type and colour of the substrate (if it is a silt or a clay, sand or a volcanic ash). These are some of the characteristics that we describe during collection of a specimen. We are hoping that you we can replicate this skill by training new eyes in finding fossils and other interesting features in these images.

1984: The discovery of Nariokotome Boy

This skull and mandible belong to the 1.6 million year old skeleton of Homo erectus found at Nariokotome on the west side of Lake Turkana, sometimes referred to as the “Turkana Boy” or the “Nariokotome Boy”. This discovery was made by Kamoya Kimeu, on a Sunday morning in August 1984. He was walking up a gentle slope on the southern side of the seasonal Nariokotome River when he spotted a matchbox sized skull fragment, which he recognized as belonging to a human ancestor. No one could have imagined that such a complete specimen would be recovered. As the excavation of the hillside progressed more pieces of skull, teeth, and then ribs began to be uncovered. This turned into one of the most exciting excavations of arguably the most important fossil discovered in east Africa.
Due to its completeness, this skeleton provides unprecedented insight into the body shape, brain size and development of Homo erectus. The Turkana Boy was surprisingly tall, 5’3” (1.6 meters) although he was still an adolescent. He had a slender body well adapted to living in hot climates. Homo erectus was the first human ancestor to migrate out of Africa 1.8 million years ago. Several specimens have also been recovered from sites in China, Indonesia, and Dmanisi in the Republic of Georgia.

A 3D scan of this fossil and others can be found at africanfossils.org

Ground Truthing the FossilFinder Beta Test

We arrived yesterday in Ileret and the first thing we just had to do was to see if we could relocate finds located by our beta testers from the images we collected last season.

One of the pictures we placed online during the beta was flagged a few times as containing numerous fossil bone fragments. Here is the picture from the preview:

An interesting image from the fossilfinder beta
An interesting image from the fossilfinder beta

GPS in hand we drove out to area 8. After a few moments of figuring out the best way to use the gps data we had we found those fossil bones on the surface:

fossil bones found during ground truthing
fossil bones found during ground truthing

This is an excellent result and means that our method is working!