Nannotax Enabling nannofossil research

I have been looking at published size ranges for Discoasters and in general they appear to be somewhat optimistic. For example in Aubry’s Handbook of Cenozoic Calcareous Nannoplankton she lists a size range of Discoaster tamalis as 10-12 microns. In general the members of this taxon I have observed have been smaller than the lower end of this range, usually in the 4-8 micron range. Similarly, D. prepentaradiatus is listed as 9-12 microns. If I saw one of these that was 9 microns I would think it was unusually large a 12 micron specimen would send me running down the hall to show somebody. These are just examples, most of the other Discoasters (also in other publications) are reported as being similarly large. Are the Discoasters of the Gulf of Mexico a dwarf population, or are authors describing giants?