The holotype ledger: 95% of new mammals come from the South, 60% of the specimens do not stay

A study by Brazilian scientists published in npj Biodiversity has counted the 1,116 mammal species described between 1990 and 2025 and asked a simple question about each one: where is the holotype ^[1][2]. Of those species, 95% were native to the Global South, while 60% of the holotypes are held in wealthy countries in Europe and North America ^[3][4]. That turns a familiar complaint into an auditable figure, which is a different kind of problem for a collections manager or a funder.

The asymmetry is visible in both directions. For species native to the Global North described in the same window, only 22% have holotypes stored outside their country of origin, and those tend to sit within the same geopolitical bloc, which the authors note can include Australia and New Zealand ^[5]. Looked at from the shelf rather than the field, more than 90% of all mammal holotypes held in the Global North were collected in a different country; in the Global South, fewer than 8% of mammal holotypes came from somewhere else ^[6][7].

Mammals are worse than comparable groups. Among freshwater fish described after 2000, 30% have holotypes outside the country of origin; among reptiles described after 1990, the figure is 50% ^[8][9]. According to Mario Moura of the Federal University of Paraiba, the study's first author, the mammal numbers were a surprise: colonial-era collecting was expected, but not persistence at this level in recent decades, and he describes the pattern as scientific neocolonialism being more pronounced in mammals than in other animal groups ^[10][11].

Brazil is the counterexample inside the dataset. It led the period with 133 new mammal species described, and 108 of those holotypes stayed in national institutions ^[12][13], which is about 81% retention ^[14] on roughly 12% of all descriptions worldwide ^[15].

The reason this matters operationally is that holotypes are working equipment, not trophies. Anyone describing a candidate new species must compare it against the holotype of the closest known relative to confirm the find ^[16]. Co-author Jhonny Guedes says accessing material from one's own country when it is held abroad requires resources that are not always available, which delays the generation of knowledge ^[17]. The authors place the results in the context of parachute science, in which researchers from the Global North collect material in the South and deposit and study it at home, often without local collaborators ^[18]. Moura's group previously found parachute science accounted for most descriptions of terrestrial molluscs ^[19], and another study he supervised found Northern countries published more robust work on Southern biodiversity, partly on the strength of better analytical equipment ^[20].

Two things to watch. First, Brazil's repatriation track: one set of dinosaur fossils has already been returned and negotiations are under way for at least one more ^[21], which will indicate whether specimen return is becoming routine or stays case-by-case. Second, whether the 60/40 holotype split starts appearing as a reported statistic per institution and per grant, since the study has made it cheap to compute for any taxon with a described-species list.