sorry I have no reference for that

My teacher used to tell us : a fossil is anything that bears witness of an extinct life. A molecule, a bone, a shell, a log, leaf cuticle, pollen, but also foot-prints, tools, feeding-marks etc.

Hello Rana; Like Marc Philippe I have no citation. The definition that I have always used is "Any indication of former life." Can't get any broader than that but it works. Best regards, Jim Des Lauriers

Fósil es todo aquel vestigio de lo que fue un animal y planta que vivió en un remoto pasado y cuyos restos se ha preservado, en general, en el interior de un sedimento.

I think that the definitions of Marc Philippe and James Des Lauriers are not entirely correct. According to these definitions, the track I left behind as I walked along the clayey bank of the river is a fossil. But that's not true. This trace must be buried in order to become a fossil. This is what makes dinosaur tracks different from mine: they were buried. Another aspect is time. Are modern cemeteries repositories for fossils? Where is the border? After all, we consider the burials of ancient people to be fossils. And it seems to me that this border is very vague.

Hello V. Yu. The only distinction between your footprint and that of the dinosaur is time. Both impressions provide infomation about setting, traits of the producer, time and more. That's what we extract from fossils and so I am inclined to stick with this old definition. Best regards, Jim Des Lauriers

For me, and I have no references either, a fossil is "any geologically modified remains or signs of the activity of past organisms." The definition includes body fossils, ichnites, exuvia, etc., but also charcoal, "fossil fuel." Exclude taxa and sediments (e.g. fossil dinosaur, fossil beach). It may be doubted whether it includes chemical traces of organic origin. The key is "geologically modified" (lithified, ferruginized, etc.).