This archive report was first published on 15 July 2019.
On July 15, 2019, a team of researchers from the National Museums of Kenya, University of Arkansas, University of Missouri, and Duke University announced the discovery of a tiny monkey fossil in Kenya, dating back 4.2 million years.
The fossil, named Nanopithecus browni, is the same size as a modern talapoin monkey, the smallest living Old World monkey species, weighing only 2 to 3 pounds. This is significantly smaller than most guenon species, which are widespread across Africa today.
Researchers believe that the evolution of guenons is poorly understood and may be driven by changes in forest habitats. However, the discovery of Nanopithecus browni in Kenya's dry and grassy habitat, far from the tropical forests of modern talapoins, reveals a more complex evolution of guenon monkeys than previously thought.
The fossil was discovered at the Kanapoi site in Kenya, where remains of early human ancestors, Australopithecus anamensis, have also been found. The discovery of Nanopithecus browni is significant, as it is the second oldest guenon found so far, and suggests that dwarfing may have occurred far longer ago than scientists suspected.
According to Fredrick Kyalo Manthi of the National Museums of Kenya, the discovery of Nanopithecus browni reaffirms Kenya's contribution to understanding the evolution and diversity of Pliocene fauna and the environmental contexts in which they lived.
