The fossil of a semi-aquatic creature unearthed in northern Canada may hold the key to how seals and walruses evolved, the BBC reports. The carnivore—which resembles a cross between an otter and a seal—had feet that were webbed but weren't flippers. Scientists believe the animals walked on land and swam in fresh water.
The find fills a crucial gap in the fossil record "when terrestrial carnivores traded limbs for fins and moved from land to sea," said one biology professor. The animal has been named Pujilla darwini. The label is based on an Inuit word for sea mammal and is a nod to Charles Darwin, who believed that land mammals likely evolved into ocean-going marine mammals via an intermediate stage in fresh water. (More fossil stories.)