Artist's impression of a type of marine predator known as Kerygmachela kierkegaardi which existed around 521 and 514 million years ago. The brains and nervous systems of 15 ancestors of modern-day spiders and insects have been found in the frozen shale of Greenland. These sea monsters are believed to have had two long appendages on their head, 11 swimming flaps and a skinny tail to help them hunt their prey, according to researchers from Bristol University. (Photo/IC)
