Armintomys

Armintomys Temporal range: 50.3–46.2 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Suborder:	Myomorpha
Family:	†Armintomyidae Dawson, Krishtalka, & Stucky, 1990
Genus:	†Armintomys Dawson, Krishtalka, & Stucky, 1990
Species:	†A. tullbergi
Binomial name
†Armintomys tullbergi Dawson, Krishtalka, & Stucky, 1990

Armintomys is an extinct genus of rodent from North America related to jerboas and jumping mice. It is the only genus in the family Armintomyidae. It lived during the early Eocene, and is the oldest known example of a hystricomorphous zygomasseteric dentition.^[1] In addition, Armintomys is also the oldest known rodent that had an incisor enamel transition from pauciserial to uniserial.^[2] Its remains have only been found in the Wind River Basin in Wyoming, and could be found there during the species' existence on Earth.^[3] It was previously assumed that Armintomys belonged to the Dipodoidea family, but has since been understood to have been part of an early radiation of dipodoid rodents, but was not directly ancestral to any later dipodoids, thus it was recategorized into its own family.^[4]

References

1. Dawson, Mary R.; Krishtalka, Leonard; Stucky, Richard K. (June 8, 1990). "Revision of the Wind River faunas, early Eocene of central Wyoming. IX - The oldest known hystricomorphous rodent (Mammalia: Rodentia)". Carnegie Museum of Natural History, Annals. 59 (2). NASA. doi:10.5962/p.240768. ISSN 0097-4463. Retrieved 3 March 2021.
2. "Mammal Species of the World - Browse: Dipodidae". www.departments.bucknell.edu. Retrieved 2022-04-13.
3. Dawson, Mary R.; Krishtalka, Leonard; Stucky, Richard K. (1990-06-08). "Revision of the Wind River faunas, early Eocene of central Wyoming. IX - The oldest known hystricomorphous rodent (Mammalia: Rodentia)". Carnegie Museum of Natural History, Annals. 59 (2). doi:10.5962/p.240768. ISSN 0097-4463.
4. Korth, William W. (2013-11-21). The Tertiary Record of Rodents in North America. Springer Science & Business Media. ISBN 978-1-4899-1444-6.