Scientists wonder if Earth once harboured a pre-human industrial civilisation

If there had been an advanced industrial age in the Silurian epoch then it would have been very different to ours.

For starters, the reason we have coal today is that during the Carboniferous epoch, ~358 to 298 MYA, the Glossopteris forests that covered large sections of the earth evolved before the bugs - termites etc. - evolved to break them down, hence we're still left with vast quantities of coal which is essentially squashed unrotted Glossopteris 'trees' (actually they're a type of primitive fern).

Presumably, a Silurian, ~443 - 419 MYA, civilization wouldn't have had these bugs either. So that must have posed major problems for them.

Alternatively, there was some kind of 'Carboniferous' epoch before the Silurian one and it and the 'termites' that came after it became extinct before the Silurian epoch began. Funny that we've not yet come across any such epoch(s).

Such extraordinary claims require extraordinary evidence.

Title needs (2018).