Scientists have unearthed marine communities thriving on a millions-year-old whale graveyard. These graveyards form when whale carcasses fall to the sea floor, becoming a sustaining snack for nearby critters. Researchers used a submersible to explore the remains in the southeastern Indian Ocean and found bones dating back 5.3 million years, as well as living creatures like jellyfish and tubeworms. The researchers say many factors likely conspired to preserve the bones, including the bones' high density, their location deep underwater and a special coating of minerals. The new study was published Wednesday in the journal Nature.