http://news.nationalgeographic.com/news/2011/02/110223-walking-cactus-worm-new-species-fossils-animals/
http://www.nature.com/news/2011/110223/full/news.2011.121.html
http://www.physorg.com/news/2011-02-cactus-rewrites-arthropod-odyssey.html
http://blogs.discovermagazine.com/80beats/2011/02/23/520-million-year-old-walking-cactus-could-be-forerunner-of-arthropods/
