One example is the ignored work of scientists dabbling in ideas that contradict neodarwinian dogma. Progress is an acknowledgment of the opposition. The new ideas reign, at least for a while, until they too become ossified and insensitive to the squawks of new anomalies, and are eventually overthrown themselves. Kuhn's model of paradigm shift in science is so convincing that it has become a paradigm itself-the paradigms of paradigms. We now see paradigms and paradigm overthrows everywhere, inside of science and out.
Paradigm shifts are our paradigm.
The fact that things don't really work that way is, well, an anomaly. Before this recognition, the peculiar facts are taken as givens or are ignored in the old framework. In other words, the real anomalies that eventually overthrow a reigning paradigm are at first not even perceived as anomalies. They are invisible. The fact that the shape of South America and Africa fit together like a lock and key did not bother any pre-1960s geologists.