Hypothetical (somewhat farfetched, but still in the realm of possibility):
A ten year old child is sliding down a slide at the local school playground when she sees something sticking out from the ground. Curious, she digs it up and admires it for a while. Thinking that she found something that might be scientifically interesting, she ditches school and spends her lunch money on bus fare to the local university, where she shows what she found to professors. One of the professors identifies the object as a "missing link" fossil and begins the process of writing up a paper for submission to a journal.
Does the child deserve authorship?
More generally, does discovering a "thing" merit authorship? Clearly, if I am on a grant-funded dig to find transitional fossils, rare crystals, paleolithic weapons, or mutant hermaphrodite hybrid lizard-bird droppings and I actually find one that turns out to be critical to the paper, I deserve authorship. Does stumbling onto a scientifically novel object by accident rather than design also merit authorship?
Similarly, if an uneducated, illiterate farmhand finds an axe in a field and it turns out the axe is a critical piece of archaeological evidence that pushes back a milestone in human civilization by a thousand years, does the farmhand deserve authorship or does authorship only fall to the one who recognizes the scientific merit of the find?
If scientific understanding of the find is required to merit authorship, what is the threshold? For example, perhaps our hypothetical child discoverer merits authorship only if she recognized that the item was a fossil. If she thought the item was a meteorite and took it to an astronomy professor, she wouldn't get authorship but would probably merit an acknowledgment ("Thanks to little Suzie Smith, age 10, who found this fossil for me on the grounds of North Town Elementary School."). If Suzie knew the item was a fossil but had no idea that it was interesting enough for a paper, would she still get authorship? What if she knew the item was scientifically interesting enough to merit a paper but did not know enough of the science to actually write the paper without help from someone actually working in academia?
If the answer or convention varies by field, an answer that covers the field(s) with which you are familiar with authorship conventions would count as a good answer. For example, "In archaeology we have a strict requirement that nobody without at least a bachelor's degree can receive authorship, but in evolutionary biology it's based on a holistic analysis of your contributions, see e.g. Smith (2002) for a summary of recent authorship disputes as it pertains to fossil discovery." could qualify.
If something like this has actually happened, explaining the scenario and what decision was made would count as an answer. For example, "Last fall, this car salesman named Donald J Robin found a 17th century manuscript in his grandmother's jewelry box that he thought was an unknown early textual variant of Hamlet. Working closely with professors at his local university, he discovered that he was correct and published a paper together with them. The professors recommended him for an accelerated double master's degree in literature and archaeology and he is scheduled to graduate this spring."
Yes, I know that this is somewhat of a far-fetched idea and acknowledge that the vast majority of people will never chance upon a major discovery like this. I do note that this is a somewhat common trope in science fiction (e.g. some ordinary "Joe" falls into a bog and comes up choking on the Missing Link and tangled up in a map to Atlantis or something), so it seems likely that such a scenario has been considered or may have even happened.