An early vertebrate with lensed eyes. Quite an advance from the Cambrian:-http://www.nytimes.com/2014/06/12/science/a-long-ago-ancestor-a-little-fish-with-incipient-jaws.html?_r=0-"This two-inch, 505-million-year-old creature belonged to the lineage that would later produce sharks, eels and other fish — along with birds, reptiles and mammals like us. This early vertebrate, known as Metaspriggina, was something of a mystery for years, known only from a pair of ambiguous fossils. But recently, scientists unearthed a trove of much more complete Metaspriggina fossils.-"As they report today in the journal Nature, the new fossils offer a remarkably detailed understanding of the first vertebrates, helping scientists understand how major parts of our own anatomy — from eyes to jaws to our muscles — evolved."