The parasites of the genus Trypanosoma have a great diversity of vertebrate hosts and can be transmitted by several groups of invertebrates. All rodent and marsupial species are potential hosts of different trypanosome species. Most species descriptions of trypanosomes have been based only on morphological characteristics. In this study, we conducted a survey on trypanosome infection in small mammals that were caught in an area of the Brazilian Pantanal (Wetlands) and Cerrado (Savanna) biomes in the state of Mato Grosso. The trypanosomes isolated were included in phylogenetic studies based on the SSUrDNA and gGAPDH genes, which were complemented through morphological studies based on scanning and transmission electron microscopy. The morphological and biological discontinuities, along with the phylogenetic position, made it possible to describe four new species of trypanosome hosted by marsupials and rodents, which we described and named as Trypanosoma daniloi sp. nov., Trypanosoma favoritoae sp. nov., Trypanosoma percequilloi sp. nov., and Trypanosoma trefauti sp. nov.
Keywords: Trypanosoma; marsupials and rodents; phylogeny; taxonomy.