Puijila represents a chapter in the story of life on Earth, offering insights into the evolutionary pathway of marine mammals. Its discovery has reshaped scientific understanding of how land animals adapted to aquatic environments.
Meet Puijila
Puijila darwini, named in honor of Charles Darwin, was an extinct species of stem-pinniped that lived approximately 21 to 24 million years ago during the Miocene epoch. This animal was about one meter (3.3 feet) long, possessing an otter-like body shape with a relatively short tail. While it lacked the flippers of modern seals, its robust forelimbs and flattened toe bones suggest it had well-developed muscles and webbed feet, indicating it was capable of both swimming and walking on land.
Puijila was a semi-aquatic carnivore, and its skull and teeth strongly link it to modern pinnipeds, a group that includes seals, sea lions, and walruses. It likely propelled itself through freshwater by paddling with both its front and hind webbed feet. Its diet likely included small prey such as ducks and rodents, indicating it hunted in both terrestrial and aquatic settings.
The Arctic Discovery
The fossilized remains of Puijila darwini were discovered in 2007 by Natalia Rybczynski and her research team on Devon Island in Nunavut, within the Canadian Arctic, specifically at the Haughton meteor impact crater. The initial discovery occurred by accident when their vehicle ran out of gas.
Subsequent expeditions, including one in 2008, unearthed a remarkably complete skeleton, almost 65 percent intact. Its unusual preservation provided extensive details about the animal’s anatomy. The fossil was found in deposits from an ancient crater lake, suggesting that the surrounding paleoenvironment during the Miocene was a cool, temperate coastal region with forests, similar to present-day New Jersey.
A Missing Link Revealed
Puijila holds significant evolutionary importance as a transitional fossil, offering a morphological link in the early evolution of pinnipeds. Before its discovery, the most primitive known pinniped, Enaliarctos, already possessed fully developed flippers, leaving a gap in the fossil record. Puijila bridges this gap, showing an earlier stage in the shift from land-dwelling carnivores to aquatic forms.
The discovery of Puijila provides evidence for the hypothesis that pinniped evolution included a freshwater phase. The ancient lakebed where the fossil was found suggests these semi-aquatic mammals adapted to freshwater environments before transitioning to marine life. This supports the idea that the Arctic may have been a central point for the evolution of the entire pinniped group.