Researchers say they have identified the oldest animal of all time and credit cholesterol, in part, for confirming the finding. Seventy-five years ago, Australian researchers in Russia discovered the creature, called Dickinsonia. After years of analysis, scientists said that molecules discovered on the fossil confirmed that that it lived 558 million years ago, making it the earliest known member of the animal kingdom. The findings place its existence 20 million years before the Cambria...