Fathoming tropical biodiversity: the continuing discovery of Neotropical mammals

. We are still far from knowing, even approximately, the number of extant mammal species. Successive attempts over the last half‐century to tally mammals of the world have produced a steadily (or perhaps exponentially) climbing total. By analysing nomenclature for Neotropical mammals, two well‐defined biases are documented that are associated with species accumulation. First, definite trends in body size are evident, so that larger organisms were more quickly apparent to systematists. Most species being described today are small‐bodied forms. Secondly, the locus of descriptive taxonomic work on this fauna has clearly shifted seriatim from continental European scientists and institutions, through British and American counterparts, to Latin American institutions. Although specifying these and other biases might focus models of species accumulation, there are no real short cuts in the global effort to inventory and document biological diversity.