This is unfortunately an invasive species (result of escapes and releases from the pet trade) as pencillata does not occur naturally in this area of Minas Gerais state (it does in the far western area where you have Cerrado though).
Historically, the buffy headed (Callithrix flaviceps) and buffy tufted marmosets (Callithrix aurita) are found in the interior of the State and the Geoffroy's marmoset (Callithrix geoffroyi) occurs along the border regions with the state of Espirito Santo.
