Xyronomys

Extinct family of mammals

Xyronomys
Temporal range: 63.3–61.7 Ma
PreꞒ
O
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C
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Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Multituberculata
Family: Neoplagiaulacidae
Genus: Xyronomys
J. K. Rigby, 1980
Species

X. swainae
X. robinsoni

Xyronomys is an extinct genus of small mammals from the Paleocene of North America, with two described species. The genus lies within the extinct order Multituberculata within the suborder Cimolodonta and family Neoplagiaulacidae.

The species Xyronomys swainae (J. K. Rigby, 1980) was found in Torrejonian (Paleocene)-age strata of Swain Quarry in Wyoming, United States. Represented by a couple of teeth, this genus was originally assigned to Eucosmodontidae. Kielan-Jaworowska and Hurum (2001, p. 406) refer it to Neoplagiaulacidae on the basis of its possession of microprismatic enamel, i.e. the tooth enamel is built up from small prisms.

A second species Xyronomys robinsoni was found in Puercan (Lower Paleocene)-age strata of Colorado, US and was named by Middleton and Dewar in 2004.

Material assigned to this genus has also been reported from Rav W-1 in Saskatchewan, Canada.

References

  • Kielan-Jaworowska, Z. and Hurum, J.H. (2001), "Phylogeny and Systematics of multituberculate mammals", Paleontology 44:389-429.
  • Rigby, J.K. (1980), "Swain Quarry of the Fort Union Formation, Middle Paleocene (Torrejonian), Carbon County, Wyoming: geologic setting and mammalian fauna", Evolutionary Monographs 3, vi +179pp.
  • Much of this information has been derived from Mesozoic Mammals: Ptilodontoidea, an Internet directory.
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Cynodontia
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Mammalia
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Allotheria
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Gondwanatheria?
Ferugliotheriidae?
Sudamericidae
Allodontoidea
Allodontidae
Paulchoffatioidea
Pinheirodontidae
Paulchoffatiidae
Plagiaulacoidea
Plagiaulacidae
Eobaataridae
Albionbaataridae
Cimolodonta
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Sunnyodon notleyi
Paracimexomys group
Cimolomyidae
Kogaionidae
Eucosmodontidae
Microcosmodontidae
Ptilodontoidea
Cimolodontidae
Neoplagiaulacidae
Ptilodontidae
Taeniolabidoidea
Lambdopsalidae
Taeniolabididae
Djadochtatherioidea
Sloanbaataridae
Djadochtatheriidae
Taeniolabis taoensis
Taxon identifiers
Xyronomys