Emily Hughes brings us tales of adventure and discovery from the Australian Outback as she and her mother search for unbelievably ancient fossils. This time, she describes to us how excavation actually works in real life.
From movies and TV, people imagine paleontology to consist of scientists in khaki shorts and a hat brushing dirt off of a dinosaur skeleton preserved perfectly under a thin layer of sand. However, though the outfits might be the same, the actual process is very different, especially when it comes to 560-million-year-old soft-bodied organisms preserved in rock.
As you may know, different fossils are found in different layers of rock. The higher up the layers are, the younger the fossils will be. Each layer of rock contains different fossils. Our job is to find these layers of rock, get them out of the ground in pieces, and then put them back together again; sort of like a puzzle.
We started a new excavation of a bed a few days ago. First, we find a place to dig, usually where there are nearby rocks on the ground with fossils on them. Afterwards, we find the edges of layers, or just the tops of them, and brush off all the dirt and sand. My brother and a student completed this step with this bed. Unlike in the movies, we get really dirty doing it, too.
After we find the bed, we map it. This is done by finding the broken-up bits of rock, and marking where they fit together. The fossils will be found on the base of the rock, so the marks don’t bother anything.
Then, we begin to remove the rocks piece by piece, and place them in their designated spot on the ground nearby. It is extremely difficult to put them back exactly as they came out, and we use a lot of our puzzle-solving skills to complete this task. But, once we do, it looks fantastic. Once the bed is out in the open, we look for the interesting fossils preserved on it. Each bed is home to new questions and new answers, and each is a mystery waiting to be solved.A reassembled fossil bed. (Photo by Emily Hughes)