Pleased to see that this paper on global patterns of spider biodiversity has been published, reporting that species richness peaks over the Equator rather than the Tropic of Capricorn, as once claimed. We must caution that this result could easily be swayed by regional differences in taxonomic effort, so these patterns should be recalculated periodically. It’s also worth noting that the equatorial pattern only emerges after correcting for the species-area power law, and most prior claims about a southern-hemispheric peak in species richness for various taxa are probably failing to make this correction. Graphs below show without the correction (left) and with the correction (right).