It may look like a cross between a seal and an otter; but an Arctic fossil could, scientists say, hold the secret of seal evolution in its feet. A skeleton unearthed in northern Canada shows a creature with feet that were probably webbed, but were not flippers. Writing in the journal Nature, scientists suggest the 23 million-year-old proto-seal would have walked on land and swum in fresh water. It is the oldest seal ancestor found so far and has been named Pujilla darwini.