Evolutionary Tree (IMAGE) University of Adelaide Caption In the evolutionary tree, Australian researchers have now grouped the mysterious, extinct creatures known as vetulicolians on a branch alongside vertebrate animals. Although not in the same direct evolutionary line, this places the 500-million-year-old marine creatures as distant cousins of humans. Credit University of Adelaide/South Australian Museum Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.