I want to know the answer to the following question:
When was the beginning of the Tonian period?
All the background I'm provided with is that "During the beginning of the Tonian period around 1 billion years ago, there was a decrease in Stromatolite diversity, which may indicate the appearance of grazing animals, since stromatolite diversity increased when grazing animals went extinct at the End Permian and End Ordovician extinction events, and decreased shortly after the grazer populations recovered.". Is that enough to answer the question?