Carne, A.; Sanchez-Vialas, A.; Lansac, C.; Moreno, M.; De la Riva, I. J.

Global biodiversity faces severe anthropogenic threats, with alarming extinction rates projected for the near future. Most of Earths diversity remains undescribed, meaning countless species are doomed to extinction before being documented. Since current conservation laws consider only described species, the time to achieve a representative inventory of global biodiversity is crucial for effective conservation. Amphibians, the most endangered vertebrate class, exemplify the challenge: while the number of threatened species rises, new species descriptions rapidly increase, and hundreds of candidate species are flagged annually worldwide. We analyzed all anuran species described from the year 2000 to 2023 across four biodiversity-rich tropical regions to investigate the time required to describe new frog species. We quantified the time needed to collect the type series, the number and timing of expeditions, the lag between collection and publication of the species description, and the total time. Additionally, we explored temporal trends and the effect of selected abiotic variables. On average, it takes 11.3 years to formally describe a frog species since the collection of the first specimen, with 4.5 years spent on specimen collection and 6.8 years on description and publication. These figures were consistent across three of the four regions analyzed. Alarmingly, the time required to describe new species is globally increasing, exacerbating the so-called taxonomic impediment. Only 36% of species were described within five years of collection, highlighting the importance of biological collections as reservoirs of undescribed diversity while also calling for specimen revision after expeditions. These results raise concerns about the effectiveness of current taxonomic and conservation practices in addressing the biodiversity crisis. We call for a global effort to prioritize taxonomic research and discuss innovative taxonomic and conservation approaches. Under current practices, and given the observed timelines, we will lose the race against extinction for many species.