Abstract The seasonal forest formations of the Atlantic Forest are a threatened and poorly known habitat. We present here a list of the non-volant mammals occurring in a 515-ha forest fragment known as Santa Maria and located in the Brazilian state of São Paulo. Our surveys are based on live trap captures, camera traps, and active searches for footprints, as well as secondary data. We list 29 species of non-volant mammals in the fragment, recorded between 1996 and 2021. One species found in the fragment, Leontopithecus chrysopygus, is globally endangered. Two species are classified as “vulnerable” in the global red list: Myrmecophaga tridactyla, and Tapirus terresris. One species, Panthera onca, is classified as “critically endangered” in São Paulo state. The red howler, Alouatta guariba, was not recorded after 1999 and has probably been extirpated in the fragment. We show that the number of non-volant mammal species in Santa Maria fragment is high, in relation to its size. The fragment is also in a strategic position, between the Morro do Diabo state park and the Black Lion Tamarin Ecological station, the two largest protected areas in the region. Considering its high mammal richness and its possible role as stepping stone for the local fauna, we recommend that the fragment become a protected area.

Resumo: Aqui nós relatamos ampliação de distribuição de três espécies de eretizontídeos amazônicos: Coendou bicolor, C. ichillus e C. nycthemera. Nós registramos pela primeira vez C. ichillus no Brasil, no Rio Japurá, estado do Amazonas. Registramos C. bicolor pela primeira vez no estado Amazonas, o que representa uma ampliação de distribuição de aproximadamente 905 km. Também estendemos a ocorrência de C. nycthemera 620 km ao sul, no estado de Mato Grosso. Todos os registros são baseados em espécimes de museu, enfatizando a importância das coleções científicas como bancos de dados da biodiversidade e a destacando ausência de pesquisas para porcos-espinhos amazônicos.

Abstract: We report range extensions for three species of Amazonian erethizontids, Coendou bicolor, C. ichillus, and C. nycthemera. We record C. ichillus for the first time in Brazil, from Rio Japurá, state of Amazonas. We record C. bicolor for the first time in the state of Amazonas, which represents a range extension of approximately 905 km. We also extend the occurrence of C. nycthemera 620 km to the south into Mato Grosso state. All records are based on museum specimens, highlighting the importance of scientific collections as biodiversity databases and emphasizing the lack of research on Amazonian porcupines.