A new Chinese fossil has accentuated the gap in evolution. this fissil has a demonstrated brain and nevous system, two sets of eyes and is the ancestor of modern spiders. Appears out of nowhere are usual with the Cambrian. Nervous tissue is the most specialized to be developed. This is a full blown animal with all the modern parts, and no precursors in previous geologic periods.:-http://www.livescience.com/40474-ancient-mega-clawed-creature-fossilized-brain.html