Measuring What We Don't Know: Biodiversity Catalogs Reveal Bias in Taxonomic Effort.

The article focuses on assessing taxonomic effort and biases in the documentation of global spider biodiversity using data from the World Spider Catalog (WSC), a comprehensive open-access taxonomic database. It introduces a novel taxonomic effort metric based on the ratio of new species descriptions to other taxonomic activities (such as synonymies and redescriptions) to identify understudied spider families and regions, revealing phylogenetic biases and highlighting families likely to yield many undescribed species. The study also examines geographic and socioeconomic influences on taxonomic effort, noting limitations due to colonial legacies and data standardization issues, and provides updated estimates of spider species diversity by family. The authors emphasize the importance of maintaining and expanding biodiversity catalogs to guide future species discovery and address global biodiversity loss.