New archaeological discoveries overturning old received wisdom is as common as any other scientific discipline, and like other sciences it is typically not done by a single discovery but rather a slow accumulation of evidence and interpretation. For example, in the past decade or so the very old debate about whether agriculture spread to Europe by farmers from the near east physically moving and planting or by the hunter gatherers already living there adopting farming practices has been settled pretty decisively in favor of the former by genetic evidence. However this was not done at once, it was the result of years of work and large interdisciplinary studies, and crucially had been preceded by anthropological works to the same effect (eg Peter Bellwood's First Farmers). So while the debate seems like it was settled rapidly, it was a pretty drawn out process.

That said there are times when a single discovery or set of discoveries can send shockwaves across a field. One example I like in part because it seems so boring and technical but is also so easy to grasp its implications is the chemical composition of the clay used to create the so-called "torpedo jars" that are common on sites on the west coast of India in Late Antiquity. For a long time they were assumed to be of Mediterranean origin, that is, these jars are the remains of the trade between India and the Roman empire. It is a fair assumption: that particular trade was flourishing, there is plenty of other contemporary evidence for Roman trade (eg coins) and in the centuries before the "torpedo jar" appeared, Roman amphora were found in some abundance. However, new analyses done by the British Museum (primarily the late Roberta Tomber) demonstrated that the clay used to make the jars was in fact most similar to clay from Mesopotamia, and thus the Persian Sassanian empire.

It is difficult to think of more technical, small scale work than looking a chunks of pottery in a microscope and describing the inclusions in the surface, but it is also hard to think of a more obviously significant conclusion than that an entire artefact class that we had thought originated from one area actually originated from a completely different area. This does not necessarily "rewrite the book", as I noted there is plenty of other evidence for Roman trade, but it does change how we characterize it. Rather than as "Indo-Roman trade", a phrase I am guilty of using, in which Romans brought wine to India and traded it for pepper, what emerges is a commercial region in which there was no one dominant party or dominant exchange. There were certainly ships that departed from Egypt's Red Sea with mostly jars of wine and returned with mostly pepper, but there were also Persian ships bringing coral that had come from the Mediterranean over the overland Palmyrene route and returning with silk that had come from China. It was a much more vibrant and complicated world.