Reconstruction and 3D Imaging
Many of the fossil bones were found in broken pieces. Many were reassembled and glued using a consolidant. These included some of the skull, as well as the limb bones and vertebrae elements.
However some fragments were too delicate to physically reattach. Fortunately, the palaeontologists were able to rely on three-dimensional scanning technology to create some virtual reconstructions of Puijila.
Almost all the bones were surface-scanned at the Canadian Museum of Nature's Arius3D Imaging Centre. The braincase was scanned using computed tomography (a "CT scan") at the Center for Quantitative Imaging, Pennsylvania State University. Working with 3D images made the skeletal reconstruction much easier and faster—and safer for the specimen—than mounting the bones would have been.
Missing bones were also reconstructed and replaced in a virtual, 3D environment. The replacement parts were based on comparisons with the Puijila skeleton and with the skeletons of other mammals, both living and fossil.
In addition to its other benefits, seeing the skull reconstructed in three dimensions gave palaeontologist Natalia Rybczynski a welcome flash of recognition: she was able to see similarities between the 3D model and the skulls of known fossil marine pinnipeds. Such similarities support the hypothesis that Puijila belongs to the pinniped group.
The 3D scans can also be used to create physical reconstructions known as "3D prints". A "printer" produces copies of the bones by alternating layers of powder and binder, which bond and form a solid. One such 3D print was mounted and displayed as part of the special exhibition Extreme Mammals. (Watch a video of a print being made).
The fossil of Puijila darwini belongs to the Government of Nunavut. (Nunavut is Canada's northernmost territory). Palaeontological material recovered from these lands belongs to the territory, and are managed on its behalf under an agreement with the Canadian Museum of Nature in Ottawa. The project team responsible for finding and studying the Puijila specimen is also based at Nature.