The Project
An aerial view of an area within the Haughton Crater.
Summary
The Puijila project is led by Natalia Rybczynski, a palaeontologist with the Canadian Museum of Nature. Rybczynski's research focuses on the evolution of Arctic mammals. She is particularly interested in the effects of geography and climate on biodiversity, through time. Some of the story is told by the Arctic fossil record.
Natalia Rybczynski and Liz Ross, still smiling despite their battle with the mud.
Accordingly, Rybczynski led research expeditions to Canada's High Arctic. A primary objective was to look for fossils of mammals that lived 24 to 20 million years ago (during the early Miocene Epoch).
The work has been productive. Most surprising was discovery of a transitional form in the evolution of pinnipeds (true seals, seal lions and the walrus). This early-Miocene swimmer, Puijila darwini, provides insights and provokes questions on how the pinniped lineage evolved through time and geographical space.
The Expeditions
Mary Dawson, Liz Ross and Natalia Rybczynski wrapping fossils in toilet paper for shipment home. Wet-screened sediment dries in the foreground. The shotguns are always kept close in case of an emergency with a polar bear.
Rybczynski and the research team went to Devon Island, Nunavut, in 2007 and 2008. Many partners provided permits and financial and logistical support for the expeditions.
The site was the Haughton Crater, where sediments indicate that it held a lake during the Miocene Epoch. This lake deposit is the only early-Miocene deposit known in the Arctic that preserves the remains of plants and animals, including vertebrates.
A further point in the locality's favour was the excellent condition of fossils found there previously (1979 to 1987). The discovery of complete and partial skeletons suggests that the lake was a quiet environment, which in turn implies that there may be more fossils. A turbulent environment would scatter the skeletal remains. Compared to the fragmentary fossils that mammal palaeontologists typically find, the prospect of discovering fossils that are largely complete and not crushed is quite attractive. Indeed, for Puijila, most of the fossil was found, as were other vertebrate fossils.
One of Puijila's teeth (the right upper incisor), at the moment of its discovery there on the ground. It is almost 2 cm long.
As part of its work, the team also collected rock samples. Some will be used to estimate the age of the impact crater. Others will also serve for reconstructing the climate that existed when the lake deposit was created. The first fossil wood from the crater was recovered.
