Tetheopsis

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title: "Tetheopsis" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["taxa-named-by-edward-drinker-cope", "dinoceratans", "fossil-taxa-described-in-1885", "prehistoric-placental-genera"] description: "Extinct genus of dinocerate mammal" topic_path: "general/taxa-named-by-edward-drinker-cope" source: "https://en.wikipedia.org/wiki/Tetheopsis" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Extinct genus of dinocerate mammal ::

| fossil_range = | image = Tetheopsis ingens.jpg | image_caption = Tetheopsis ingens | taxon = Tetheopsis | authority = Cope, 1885 | subdivision_ranks = Species | subdivision = * T. stenops (Marsh, 1885)

• T. ingens (Marsh, 1885)
• T. speirianus (Osborn, 1881) | synonyms = * Tinoceras stenops (Marsh, 1885)
• Tinoceras ingens (Marsh, 1885)
• Loxolophodon speirianus (Osborn, 1881)

Tetheopsis is an extinct genus of dinocerates from Eocene North America. The name of the genus derives from the Greek "tethe" (meaning "grandmother") and "opsis" (meaning "appearance"). Tetheopsis has only been found in the Washakie Basin, with all specimens being found on or near Haystack Mountain.

Description

::figure[src="https://upload.wikimedia.org/wikipedia/commons/9/95/Tetheopsis_ingens_2.jpg" caption="Skull of ''Tetheopsis ingens''"] ::

Tetheopsis resembles other large dinocerates like Uintatherium and Eobasileus in general morphology, but differs in skull proportions. The parietal horn is located near the occiput, and the maxillary horn is situated above the diastema (tooth gap). The genus bears the prominent canines typical of the derived uintatheriids.

Classification

Tetheopsis has been suggested to be a synonym of the related genus Eobasileus by some authors, though there is a lack of sufficient research to fully synonymize the genus. The below cladogram is based on the work of Scott and colleagues (1998):

References

References

1. "Fossilworks: Tetheopsis".
2. Wheeler, Walter. (1961-01-01). "Revision of the uintatheres". Bulletin of the Peabody Museum of Natural History.
3. Janis, Christine M.. (1998-05-28). "Evolution of Tertiary Mammals of North America: Volume 1, Terrestrial Carnivores, Ungulates, and Ungulate Like Mammals". Cambridge University Press.
4. Osborn, Henry Fairfield. (1881). "A Memoir Upon Loxolophodon and Uintatherium: Two Genera of the Sub-order Dinocerata". Princeton University.
5. Turnbull, William D.. (2002). "The mammalian faunas of the Washakie Formation, Eocene age, of southern Wyoming". Chicago, Ill. : Field Museum of Natural History.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::