Xyronomys

Xyronomys is a small mammal from the Paleocene of North America. A second species is awaiting publication. It was a genus within the extinct order Multituberculata within the suborder Cimolodonta and family Neoplagiaulacidae.

Genus: Xyronomys Rigby JK, 1980

Aka: Xironomys
Material has also been reported from Rav W-1, Saskatchewan. The genus may belong to Eucosmodontidae. However, according to more recent research, it doesn't seem to.

Species: Xyronomys swainae Rigby JK, 1980

Place: Swain Quarry, Wyoming, USA

Age: Torrejonian (Paleocene)

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; ie. the tooth enamel's built up from small prisms.

Species: Xyronomys robinsoni (Unpublished)

Place: Colorado, USA

Age: Puercan (Lower Paleocene)

Reference: Rigby (1980), Swain Quarry of the Fort Union Formation, Middle Paleocene (Torrejonian), Carbon County, Wyoming: geologic setting and mammalian fauna. Evolutionary Monographs, 3, vi+179pp.
Page reference: Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". Paleontology 44, p.389-429.