This is the skull of someone's pet dog from more than 30,000 years ago. It was buried with a mastodon bone clenched in its chompers. Found in Czech Republic by archaeologist Mietje Germonpré of Belgium's Museum of Natural History and colleagues, it's one of three canid crania they discovered from the era. The skulls support other recent research suggesting that dogs were domesticated 15,000 years earlier than previously thought. This news is one of Archaeology magazine's "Top 10 Discoveries of 2011."