Notharctus

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title: "Notharctus" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["notharctinae", "prehistoric-primate-genera", "eocene-primates", "ypresian-life", "lutetian-life", "bartonian-life", "wasatchian", "bridgerian", "uintan", "eocene-mammals-of-north-america", "fossils-of-the-united-states", "fossils-of-colorado", "paleontology-in-nevada", "paleontology-in-new-mexico", "paleontology-in-texas", "paleontology-in-utah", "fossils-of-wyoming", "fossil-taxa-described-in-1870", "taxa-named-by-joseph-leidy"] description: "Extinct genus of primates" topic_path: "science/earth-science" source: "https://en.wikipedia.org/wiki/Notharctus" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Extinct genus of primates ::

| taxon = Notharctus | authority = Leidy, 1870 | fossil_range = Early-Mid Eocene (Wasatchian-Uintan) ~ | image = Notharctus AMNH.jpg | image_caption = Notharctus tenebrosus | subdivision_ranks = Species | subdivision = {{plainlist|

• N. pugnax
• N. robustior
• N. tenebrosus
• N. venticolus}} | synonyms = * Hipposyus Leidy 1872
• Limnotherium Marsh 1871
• Telmalestes Marsh 1872
• *Thinolestes * Marsh 1872
• Tomitherium Cope 1872

Notharctus is a genus of adapiform primate that lived in North America and Europe during the early to middle Eocene. ::figure[src="https://upload.wikimedia.org/wikipedia/commons/a/ae/Notharctus_tenebrosus_e_Plesiadapis_cooki_(cropped).jpg" caption="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 40 cm in length, excluding the long tail.

There were at least four different Notharctus species. Fossils from at least seven other potential species have also been discovered. ::figure[src="https://upload.wikimedia.org/wikipedia/commons/1/17/Notharctus_osborni.JPG" caption="''N. osborni'' skull"] ::

References

Bibliography

References

1. (1999). "The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals". Marshall Editions.

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