The Expeditions
Work Life
Natalia Rybczynski prospecting for fossils at the rim of the Haughton Crater.
With 24 hours of sun, the team could work day or night. They usually tried to keep on a normal workday schedule, however. It was necessary only sometimes to extend the work into the sunny nighttime.
Prospecting for fossils involves a lot of walking. In the Haughton Crater where the team was, most of the walking was up and down hills. Many days in a field season can be taken up with prospecting.
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Once a fossil site is identified, the work focuses on extracting fossils. The first step is to collect from the surface. Fortunately, the crater's sediment is loose. Once the work moves below the surface, the sediment is sifted through a series of screens. From screen to screen, the holes get progressively smaller. Finally, residual sediment in each screen is searched for bone. If the light is good, this can be done in the field, although the lab is usually preferable for going through the smaller-sized grains.
Most of the crater sediment could be screened dry. Sediment that was clumped, however, was soaked inside screen bags in the creek, to help break the clumps apart. The team's ATV and trailer were especially useful for moving bags of sediment from the site to the creek.
Natalia and Liz Ross washing sediment away by wet-screening in the creek near camp.
Mary Dawson and Natalia puzzling over fossils in the kitchen/work tent.
In 2007, conditions were favourable, so Rybczynski and team-member Mary Dawson were able to get a lot of work done on the most promising fossil. They left the field that year already knowing that they had found a new prehistoric mammal, and that it had been a swimming carnivore.
Having life-sized photos of Puijila's skull on hand during the second expedition helped Natalia and Mary figure out if they'd found the piece they were looking for. They laid the brain-case on top, and were delighted to see how nicely it fit!
The discovery proved so exciting that it was worth another expedition in 2008 to try to find a missing piece of the skull: the braincase. It was recovered within minutes of the team's arrival at the site! Rybczynski had brought life-sized photos of the rest of the fossil, and she was able to see immediately how the braincase fit in. By the end of the day, and even without the specialized equipment back in the lab, the researchers' mental image of the shape of the animal's head had changed significantly.
