WI Earth never contained coal or petroleum?

Coal deposits are largely formed from the remains of plants in swampy areas. The oldest coal deposits (IIRC, they're late Devonian in age) are hence only somewhat younger than the oldest land plants (land plants start in the Silurian). The largest coal deposits in Europe and North America were formed in aequatorial swamps during the Carboniferous period (which is hence named 'coal-bearing' for obvious reasons. In other parts of the world, coal deposits have different ages. For example the vast coal deposits in China are of Jurassic age. :)

Oil, OTOH, is largely formed from single-celled, marine organisms.

Thank you for saying it better than I could. My point was simply that life existed before coal, so no coal does not necessarily mean no life.
 
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