I want to know the answer to the following question:
What period started around 472 million years ago?
All the background I'm provided with is that "Palaeontologists disagree about whether some body fossils from the mid Ordovician, about 472 to 461 million years ago, are the remains of oligochaetes, and the earliest indisputable fossils of the group appear in the Tertiary period, which began 65 million years ago.". Is that enough to answer the question?
Answer: yes