Abstract
Terrestrial isopods (Isopoda: Oniscidea), commonly known as woodlice, are among the most recognisable soil-dwelling inver-
tebrates and are crucial for soil functioning. They are widely distributed from temperate to equatorial ecosystems, and their
distribution is strongly influenced by environmental factors, such as soil type, temperature and humidity. Terrestrial isopods have
fascinated taxonomists for centuries, with over 4,100 described species across 568 genera and 38 or 39 families. These animals
contribute significantly to key ecosystem processes, such as litter decomposition, nutrient cycling, and carbon sequestration.
However, data on patterns of their diversity, abundance, or biomass, which are crucial for assessing their importance in ecosystem
functioning worldwide, are lacking. This is partly due to the incomplete taxonomy in regions such as the tropics and the scattered
nature of local georeferenced datasets. To better understand the global taxonomic patterns, species distributions, and functional
roles of terrestrial isopods, we call for the compilation of a comprehensive global database that integrates taxonomy, georeferenced
species records, and trait data. This database would help answer fundamental questions about the response of terrestrial isopods to
environmental changes and their role in ecosystem functioning and soil health. OniscidBase, a recently launched initiative, aims
to consolidate such data, facilitating the analysis of taxonomic gaps and assessing the distribution and functional importance of
terrestrial isopods. The database aims to include georeferenced data on the distribution, abundance and biomass of terrestrial iso-
pod species, and metadata on environmental parameters. Our main goals are to strengthen the taxonomic backbone for terrestrial
isopods, make distribution data available for macroecological studies, and collect trait data to understand species responses to en-
vironmental changes and effects on soils. Using these data leads to a deeper understanding of the importance of terrestrial isopods
as components of terrestrial ecosystems and, at the same time, highlights future research directions.