Olsen makes a splashy style statement at the American Museum of Natural History in N.Y.C. Plus: Paris & Benji, Will Smith, Cameron Diaz and more

DINO MIGHT!

No bones about it, Mary-Kate Olsen brings her star power – and unique fashion sense (in a Chloe dress) – with her Tuesday to the Roberto Cavalli-sponsored Winter Dance, held at New York's famed American Museum of Natural History.