This is certainly an interesting possibility that I have seen mentioned a few times in popular culture, but not really explored in scientific literature. If a species made it to sapience without significant tool use then we would have little sign of their existence or, at the very least, very little indication of their intellectual abilities. However certain artifacts (such spear tips and arrowheads) could have left remnants which could be identified millions of years later, especially if constructed from graphite. Anything more advanced than that, such as industrial-age technology and settlement, could have left even more significant signs of habitation, including signs of climate change and remnants of fossil fuel use (including an unexpected depletion of the expected amount of fossil fuels in the ground) and as we have not found those that probably indicates no prior civilization rose to that level before humanity. This is born out in part by the findings in the linked study, where they indicate:
“Impacts to warming and/or carbon influx (such as increase runoff, erosion, etc.) appear to be qualitatively similar whenever in the geological period they occur,” [...] “These changes are thus not sufficient evidence for prior industrial civilizations.”
That being said a proto-civilization without the use of fire and only primitive tool use should not necessarily be ruled out, as the evidence of such a civilization would be minimal after tens of millions of years.
