Notharctus is a genus of adapiform primate that lived in North America and Europe during the late to middle Eocene.[1]
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 40 centimetres (16 in) in length, excluding the long tail.[2]
There were at least four different Notharctus species.[1] Fossils from at least seven other potential species have also been discovered.[citation needed]