One of the observations made about the Neandertal (I'm going to bring it up, although it probably won't be brought up because it won't be very common knowledge) is that current data suggest that Neandertal didn't eat fish. However, during much of their sojourn in Europe, the bulk of their population would have lived on lands now flooded and at that time warmer and richer in food supply. :')
Neanderthals didn't eat fish? How surprising, when fish were so plentiful. Images of Native Americans spearing fish in the streams comes to mind.