For the study associated with this dataset, we created a database of lost and rediscovered tetrapod species and identified patterns in their distribution and factors influencing rediscovery. This appendix provides a list of the lost and rediscovered species and all data used to calculate 11 variables (V):

• V1: Taxonomic status - class, order, family, species name, common name;
• V2: Countries / islands occupied by each species;
• V3: The cumulative number of lost and rediscovered species - four columns, (i) last seen date, (ii) rediscovered date, (iii) for rediscovered species, the number of years lost, (iv) for lost species, the number of years lost;
• V4: Time lost (the number of years each species has been lost for);
• V5: Adult body mass (g) of each species;
• V6: Habitat breadth - the number of broad habitat types occupied by each species;
• V7: Habitat type - the broad habitat types occupied by each species;
• V8: Small island / mainland - whether a species occupies a small island (< 20,000 km²) or a mainland location (including islands > 20,000km²) (0 = mainland, 1 = small island);
• V9: Threats - the different threats associated with each species;
• V10: Human development - the highest level of human development across the range of each species, measured using the Human Development Index (HDI);
• V11: Survey effort - the level of effort invested in searching for each species (1 = low, 2 = medium, 3 = high, 4 = very high). See Supporting Information (Table S1) for the methods used to calculate this variable.

Please refer to the published paper associated with this dataset, which provides a detailed description of the data collection methods.