Notharctus is a genus of adapiform primate that lived in North America and Europe during the late to middle Eocene.The body form of Notharctus is similar to that of modern rats. Its fingers were elongated for clamping onto branches, including the development of a thumb. Its spine is flexible and the animal was about 40cm (20inches) in length, excluding the long tail.[1]
There were at least four different Notharctus species. Fossils from at least seven other potential species have also been discovered.