I want to know the answer to the following question:
What era was underway 505 million years ago?
All the background I'm provided with is that "Until 2008 the earliest fossils widely accepted as annelids were the polychaetes Canadia and Burgessochaeta, both from Canada's Burgess Shale, formed about 505 million years ago in the early Cambrian.". Is that enough to answer the question?
Answer: yes