Notharctinae

Notharctus is a genus of adapiform primate that lived in North America and Europe during the early to middle Eocene. left|thumb|N. tenebrosus (left) compared to Plesiadapis|Plesiadapis cookei (right), a plesiadapiform. Both come from [[Eocene Wyoming, though the latter is slightly geologically older (Museum of Natural Sciences, Brussels).]] 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 in length, excluding the long tail.

Notharctinae is an extinct subfamily of primates that were common in North America during the early and middle Eocene (55-34 million years ago). The six genera that make up the group (Cantius, Pelycodus, Copelemur, Hesperolemur, Notharctus, and Smilodectes) contain species that are among the most primitive of the adapiform group, which is one of the most primitive groups of primates. The evolutionary history of this subfamily has been comparatively well documented and has been used to argue for evolutionary gradualism. Though it is generally accepted that adapiforms gave rise to modern day lem

Cantius is a genus of adapiform primates from the early Eocene of North America and Europe. It is extremely well represented in the fossil record in North America and has been hypothesized to be the direct ancestor of Notharctus in North America. The evolution of Cantius is characterized by a significant increase in body mass that nearly tripled in size. The earliest species were considered small-sized and weighed in around , while the later occurring species were considered medium-sized and likely weighed in around . Though significantly smaller, the fossil remains discovered of the various s

Smilodectes is a genus of adapiform primate that lived in North America during the middle Eocene. It possesses a post-orbital bar and grasping thumbs and toes. Smilodectes has a small cranium size and the foramen magnum was located at the back of the skull, on the occipital bone.

species of mammal (fossil)

Pelycodus (from Ancient Greek πέλυξ (pélux), “bowl” + ὀδούς (odoús), “tooth”) is an extinct genus of adapiform primate that lived during the early Eocene (Wasatchian) period in Europe and North America, particularly Wyoming and New Mexico. It is very closely related to Cantius and may even be its subgenus. It may also have given rise to the Middle Eocene Uintan primate Hesperolemur, although this is controversial. From mass estimates based on the first molar, the two species, P. jarrovii and P. danielsae, weighed 4.5 kg and 6.3 kg respectively and were frugivores with an arboreal, qu