Alagomyidae is a family of

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s known from the late

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

and early

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

(McKenna and Bell, 1997). Alagomyids have been identified as the most basal rodents, lying outside the common ancestry of living forms (Meng et al., 1994). Because of their

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

position and their conservative dental morphology, alagomyids have played a key role in investigations of the origins and relationships of rodents (Meng et al., 1994; Meng and Wyss, 2001).

References

*McKenna, Malcolm C., and Bell, Susan K. 1997. ''Classification of Mammals Above the Species Level.'' Columbia University Press, New York, 631 pp. *Meng, J., A.R. Wyss, M.R. Dawson, and R. Zhai, 1994. Primitive fossil rodent from Inner Mongolia and its implications for mammalian phylogeny ''Nature'' 370:134-136. *Meng, J., and A.R. Wyss, 2001. The morphology of ''Tribosphenomys'' (Rodentiaformes, Mammalia): phylogenetic implications for basal Glires ''Journal of Mammalian Evolution'' 8(1):1-71. Paleocene rodents Eocene rodents Paleocene first appearances Eocene extinctions {{paleo-rodent-stub