Mammalian diversity and conservation status of Brazilian primates: insights from a museum collection

Abstract Brazil harbours one of the highest levels of primate species richness and endemism globally, with its taxonomic diversity extensively documented in preserved specimens across major biological collections worldwide. A systematic survey of primate specimens in the mammal collection of the Museu de Zoologia of the Universidade de São Paulo (MZUSP) was carried out, analysing their taxonomic and geographical coverage as well as the conservation status of the species. A total of 2416 specimens belonging to 18 genera and 85 species were reviewed and georeferenced. Most specimens originate from tropical rainforests within two distinct Brazilian biomes: Amazonia (1601) and the Atlantic Forest (487). Among the specimens in the collection, 35 are classified as threatened on the IUCN Red List: six as Critically Endangered, 12 as Endangered, and 17 as Vulnerable. The Critically Endangered species include the southern muriqui (Brachyteles arachnoides), the northern muriqui (Brachyteles hypoxanthus), Coimbra-Filho’s titi monkey (Callicebus coimbrai), Barbara Brown’s titi monkey [Callicebus (Callicebus) barbarabrownae], Vieira’s titi monkey (Plecturocebus vieirai), and the yellow-breasted capuchin (Sapajus xanthosternos). Some specimens of these five Critically Endangered species were collected from localities where the species no longer occur. Collectively, these records document past extirpation events and reveal the scale of population losses. There are eight primate type specimens held at the MZUSP collection, three of which are currently recognized as valid species. This collection represents a vital scientific resource for taxonomic, genetic, and conservation studies, and its long-term preservation is essential to safeguard its potential for future discoveries.