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Mapping the Past

Emily Hughes brings us tales of adventure and discovery from the Australian Outback as she and her mother search for unbelievably ancient fossils. Her team digs up the creatures that form the evolutionary boundary between microorganism and animal—the Ediacaran biota. 

When we are young we need to memorize maps. We color in the countries of Europe or the states of the United States. As we get older we start to use maps, and we tend to think that everything has been mapped. We can find a coffee shop, a gas station or our way to a swim meet easily enough. However, it turns out that there is still a great deal of mapping to be done. Usually, the art of map-making is not thought of as being interconnected with paleontology, but I’m here to tell you that this is not actually the case—the two depend on each other.

In our line of work (that is, working in the middle of the Australian Outback), there are four kinds of maps necessary for paleontologists to find fossils. The first involves understanding the geology of a region. We use maps that have already been made of South Australia to pinpoint the areas where we believe there will be fossils.

The next step is figuring out what facies (pronounced “fash-eeze”) are present at the site. Facies describe what kind of environment the fossils would have lived in, whether shallow water or deep water, and so on. Dr. Jim Gehling, esteemed paleontologist at the South Australian Museum, and an important member of our team, has constructed these maps so that we know where to look for a certain environment or type of fossil.

Dr. Jim Gheling spends a large amount of time mapping localities. (Photo by Dennis Rice)
Dr. Jim Gehling spends a large amount of time mapping localities. (Photo by Dennis Rice)

After we’ve identified the facies, we can use those maps to locate fossil outcrops. This seems like an obvious step, but it actually takes a lot of time, sweat, and fly nets. I have a theory that there’s a correlation between the amount of flies on your face and how tired you are. We use a handy GPS to mark localities, so that we can find the same fossils again. I spent a large amount of time attempting to master the ways of the elusive and mysterious GPS, and here’s a photo to prove it.

Here's me, working away at unlocking the secrets of the GPS (Photo by Mary Droser)
Here’s me, working away at unlocking the secrets of the GPS. (Photo by Mary Droser)

In this field season, we are mapping all of the localities with fossils preserved in 3D so that we can excavate them. I’m someone who tends to get sick at 3D movies, but that hasn’t happened here… though I did just look at the massive pile of 3D fossils that are twisted and mangled in the rocks, and my stomach did a flip-flop. More on these new fossils later, after my stomach has settled.

Last, but certainly not least, is the mapping of individual fossils on each bed. Believe it or not, we have to mark every last fossil on the bed, so that we know where it is later on, and can begin to understand relationships between each organism. Our method involves drawing one-meter-by-one-meter-chalk lines across the bed, giving coordinates to each fossil. If you have spent a few hours drawing very straight lines on the sidewalk, you’ll understand how that feels. This process takes a long time, but the result is a colorfully marked-up bed and a fancy map.

Here is one of beds we work on, all the fossils are labeled. (Photo by Mary Droser)
Here is one of beds we work on, with all of the fossils labeled. (Photo by Mary Droser)

The mapping process may not be the most exciting aspect of paleontology (though in my humble opinion, it beats wandering around trying to find fossils), but it certainly is a vital one. If anybody expects anything to come out of the fantastic paleontology we do here, they’d better be prepared for maps upon maps upon maps.

Read More by Emily Hughes