The Roosmalens dwarf marmoset[1], also called the black-crowned Pygmy marmoset or black-crowned dwarf marmoset is a New-World monkey endemic to the Amazon rainforest west of the Aripuana River and the east bank of the lower Madeira River in Brazil.
- The upper parts of the Roosmalens dwarf marmoset are mostly dark olive-brown, while the underside is pale, yellowish, and dull.
- A crown of whitish hair frames the pale, bare pinkish face. The crown is blackish, as the alternative common name suggests; black-crowned pygmy marmoset.
- The species has claws instead of nails like other common marmosets that feed on tree sap. Also, it has teeth similar to other common marmosets.
