''Guilielmofloweria'' is an extinct genus of proterotheriid

litoptern Litopterna (from "smooth heel") is an extinct order of South American native ungulates that lived from the Paleocene to the Pleistocene-Holocene around 62.5 million to 12,000 years ago (or possibly as late as 3,500 years ago), and were also pres ...

that lived from the Middle to Late Eocene of what is now

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. Fossils have been found in the

Sarmiento Formation The Sarmiento Formation (Spanish language, Spanish: ''Formación Sarmiento''), in older literature described as the Casamayor Formation, is a geological formation in Chubut Province, Argentina, in central Patagonia, which spans around 30 million y ...

of Argentina.

Taxonomy

''Guilielmofloweria'' was first named in 1901 by Florentino Ameghino based on fragmentary remains found in the Sarmiento Formation of Argentina, in rocks dating back to the Middle Eocene. He originally considered it a member of the

pantodont Pantodonta is an extinct suborder (or, according to some, an order) of eutherian mammals. These herbivorous mammals were one of the first groups of large mammals to evolve (around 66 million years ago) after the end of the Cretaceous. The la ...

family

Pantolambdidae Pantolambdidae is an extinct family of pantodont mammal in the order Pantodonta Pantodonta is an extinct suborder (or, according to some, an Order (biology), order) of eutherian mammals. These herbivorous mammals were one of the first groups ...

, but recent studies have shown this to be incorrect, as Richard Cifelli considered it as a member of the litoptern family Proterotheriidae, more specifically within the subfamily Anisolambdinae. Anisolambdinae (also called Anisolambdidae in some studies) was proposed to unite the primitive and earlier forms '' Anisolambda'', '' Eolicaphrium'', '' Heteroglyphis'', '' Lambdaconops'', '' Paranisolambda'', '' Protheosodon'', '' Wainka'' and '' Xesmodon''. However, the phylogenetic analysis of McGrath and colleagues recovered the included genera to neither form their own clade, or to universally represent basal taxa outside the genera of Proterotheriinae per Soria, making Anisolambdinae a

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

group of unrelated organisms.

References

{{Taxonbar, from=Q113961687 Proterotheriids Prehistoric placental genera Eocene mammals of South America Divisaderan Mustersan Paleogene Argentina Fossils of Argentina Fossil taxa described in 1901 Taxa named by Florentino Ameghino Golfo San Jorge Basin Sarmiento Formation