The pre-historic plesiosaur: it looked like the quintessential sea monster. It had a long neck, flippers and fangs. Think of the Loch Ness monster, and you are on the right track. But a paper published today in the journal "Science" says these ancient beasts may have actually been social creatures and doting mothers. The research is based on a fossil of a pregnant plesiosaur that's part of the new dinosaur exhibit at the Los Angeles Natural History Museum. Reporter Sanden Totten paid the specimen a visit.