Local expertise anchors biodiversity documentation, but geopolitical power drives parachute discovery.

Global biodiversity documentation is limited by a persistent biodiversity knowledge split, in which high biodiverse nations have their specimens extracted and housed elsewhere. Holotypes, the name-bearing specimens required for the description of new species, are central to this imbalance. We investigated how geopolitical and socioeconomic factors shape the deposition of mammalian holotypes described over the past 35 years. While 95% of post-1990 mammal discoveries originated in the Global South, 60% of their holotypes are housed abroad, mainly in Global North institutions. Wealthier nations extracted holotype specimens disproportionately, especially from biodiverse regions with weak environmental policies, despite stronger local academic capacity improving retention. Maintaining these inequalities not only hampers efforts to reduce disparities in the distribution of type material, but also limits the discovery and revision of species. Addressing these disparities requires coordinated structural investment in local collections and taxonomic capacity, governance measures that prioritize regional deposition and equitable specimen management, and access policies that improve repatriation, mobility, and shared control over type material.