News Earth Ancient fossil sheds light on early evolution of body armor ‘Walking cactus’ appears to have been first of its kind to stride on bendable, hard-covered legs By Susan Milius February 24, 2011 at 4:05 pm - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Click to share on Facebook (Opens in new window) Facebook Click to share on Reddit (Opens in new window) Reddit Click to share on X (Opens in new window) X Click to print (Opens in new window) Print Fossils of an ancient “walking cactus” suggest how ancestors of today’s lobsters, insects, spiders and related groups went from squishy to spiky. MEET SPIKY A depiction of the 520-million-year-old fossil Diania cactiformis in life.