A Very Old Worm

The Great 2013 Catch-upIn Ancient Fossil Looks Like Today’s Acorn Worms (8 April 2013) Brian Thomas makes a living fossil claim – sort of. “Acorn worms” are more formally known as “enteropneusts,” which is a taxonomical class containing four families and around 90 living species. The rediscovery of a collection of old finds from the Burgess Shale apparently pushes the age of the earliest acorn worms back 200 million years to around 500 million years ago, i.e. the Cambrian explosion. Continue reading