Paramys

Paramys Temporal range: Late Paleocene - Middle Eocene
Skull
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Suborder:	Sciuromorpha
Infraorder:	Protrogomorpha
Family:	† Ischyromyidae
Genus:	† Paramys Leidy, 1871
Species
P. adamus P. atavus P. compressidens P. copei P. delicatior P. delicatus P. excavatus P. hunti P. nini P. pycnus P. simpsoni P. taurus

Paramys is an extinct genus of rodents from North America, Europe, and Asia. It is one of the oldest genera of rodents known and probably lived in trees. While the genus name literally means "near a mouse", ^[1] it coexisted with Thisbemys, a similar rodent, thus yielding a reference to Pyramus and Thisbe.

Description

The brain of both the Early Eocene P. copei and the Middle Eocene P. delicatus was characterised by a lower neocortical surface area, smaller paraflocculi, and larger olfactory bulbs relative to total endocranial volume of later rodents, and they both possessed encephalisation quotients higher than that of Ischyromys typus . ^[2]

Palaeobiology

P. delicatus possessed more robust limbs and could apply a greater mechanical advantage using its limbs relative to most living squirrels, including living semi-fossorial squirrels. This suggests that it was a semi-fossorial animal that was adapted for scratch-digging. ^[3]

References

1. "Glossary. American Museum of Natural History". Archived from the original on 20 November 2021.
2. Bertrand, Ornella C.; Amador-Mughal, Farrah; Silcox, Mary T. (27 January 2016). "Virtual endocasts of Eocene Paramys (Paramyinae): oldest endocranial record for Rodentia and early brain evolution in Euarchontoglires". Proceedings of the Royal Society B: Biological Sciences . 283 (1823) 20152316. doi:10.1098/rspb.2015.2316. ISSN   0962-8452. PMC   4795019 . PMID   26817776.
3. Prufrock, Kristen A.; Ruff, Christopher B.; Rose, Kenneth D. (9 November 2020). "Locomotor Behavior and Body Mass of Paramys delicatus (Ischyromyidae, Rodentia) and Commentary on Other Early North American Paramyines" . Journal of Mammalian Evolution . 28 (2): 435–456. doi:10.1007/s10914-020-09523-8. ISSN   1064-7554 . Retrieved 10 July 2025– via Springer Nature Link.

Further reading

• Matthew, W. D. 1910. On the osteology and relationships of Paramys and the affinities of the Ischyromyidae. Bulletin of the American Museum of Natural History, 28:43–72.
• Kenneth D. Rose, 2006. The Beginning of the Age of Mammals. The Johns Hopkins University Press. Baltimore MD. pp. 306–335
• Kenneth D. Rose and Brenda J. Chinnery. The Postcranial Skeleton of Early Eocene Rodents. Bulletin of Carnegie Museum of Natural History. Volume 36, Issue 1 (December 2004): pp. 211–244
• Tullberg, T. 1899. Ueber das System der Nagethiere. Eine Phylogenetische Studie. Nova Acta Regiae Soc. Scient Upsala, ser. 3, vol. 18: v + 514 pp., 57 pls
• Wodd A. E. 1962. The Early Tertiary rodents of the family Paramyidae. Transactions of the American Philosophical Society. new series 52(1): 1–261.

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