Habitat of the Animal
Forests in the Arctic?
When Puijila darwini was alive more than 20 million years ago, its habitat was very different from the current, High-Arctic environment.
The fossil was found in Canada on Devon Island, which is within the Arctic Circle. The locality would have been at a similar latitude during Puijila's time—the early Miocene Epoch. As today, the summers provided 24 hours of sunlight, and the winters were dark. Consequently, the early-Miocene climate was highly seasonal, albeit much warmer than present.
Despite the Arctic light regime, the Miocene Arctic was a forested environment with ample understorey of smaller trees and shrubs among the taller trees. The fossil-pollen record indicates that larches and alder were dominant, and that spruce, fir, pine, birch, chestnut, and sweetgum were also present. Grasses were absent or very rare.
The humid, cool temperate, coastal climate would have had moderate winters with some periodic freezing. A roughly comparable climate is found in the northeastern United States; the comparison is suggested by the similarities in the plants in the two regions.
Today, the location is a stark, polar desert, frequently crossed by polar bears. It lies within the Haughton Crater, where low hills of pale breccia (rubble generated during the impact) are found throughout. The only significant amount of plant life in the crater is found on the yellowish, fossil-bearing deposits of the Haughton Formation.
Climate Change and Arctic Forests
The Arctic was forested for most of the Age of Mammals (65 million years ago to present). The forests disappeared roughly 3 million years ago, with the onset of the last ice ages.
Arctic forests have changed over time in response to changing global climate. About 50 million years ago, the global climate was extremely warm. Winters were ice-free, and rainforests grew in the Arctic.
The Miocene Epoch represents a transitional time between that much warmer past and the present, much-cooler ice-age climate.
The Haughton Crater is the only early Miocene-age site in the Canadian Arctic that provides a glimpse of what the Arctic would have looked during this important transitional time.
The Miocene Globe
During the Miocene Epoch, the continents were in only slightly different positions from where they are now, and their shapes are recognizable. In the Miocene Arctic, the land mass under Puijila's feet was continuous and connected with Greenland and Asia. (Now, the land is fractured into islands, and the continental connections are broken). The location where the Puijila fossil was found is indicated on the map.