Cryptic species diversity should not be trivialised

Cryptic diversity, defined as two or more distinct species that were classified as a single one due to morphological similarity, is believed to be a potentially important factor influencing future conservation decisions. A recent meta-analysis allegedly demonstrated that the proportion of cryptic species is almost evenly distributed among major metazoan taxa and biogeographical regions - a conclusion of potentially profound impact on biodiversity assessment and conservation. We argue that this result is the consequence of methodological error, and using the same data, show that the degree of cryptic diversity between metazoan phyla varies up to two orders of magnitude. Cryptic diversity is a non-trivial, genus level phenomenon that, because of its apomorphic nature, should not be generalised across all Metazoa.