The newly found monkey was first spotted by scientists in 2007 in the Brazilian state of Amazonas and is related to the saddleback tamarin monkeys, known for their distinctively marked backs, the Wildlife Conservation Society (WCS) said.

The small monkey, which is mostly gray and brown and weighs 213 grams (0.47 pound), has been named the Mura's saddleback tamarin after the Mura Indian tribe of the Purus and Madeira river basins where the new sub-species was found. It is 240 millimeters (9.4 inches) tall with a 320 millimeter (12.6 inch) tail.

"This newly described monkey shows that even today there are major wildlife discoveries to be made," Fabio Rohe, the lead author of a study confirming the new discovery, said in a statement released by the WCS.

Researchers from Karlsruhe's Natural History Museum found the 3-millimeter-long (0.118 inch) insect in the Amazon rainforest in 2007, and hope it will shed light on the early evolution of ants.

"It's by far the most spectacular find of my 26-year career," said museum biologist Manfred Verhaagh on Tuesday.

Scientists from Karlsruhe originally found an unidentified species of ant of a similar type in the Brazilian rainforest in 2003. However, due to an accident in the laboratory, the insect dried up, making further research impossible, Verhaagh said.

Last year a separate team from the museum's research body was in the forest investigating fungus when they stumbled upon the tiny insect, and named it "Martialis heureka".