Nesoryzomys indefessus indefessus Thomas, 1899:280

Indefatigable Galápagos mouse, Santa Cruz nesoryzomys, Indefatigable rice rat



Taxonomy & Nomenclature

Synonym/s: Oryzomys indefessus Thomas, 1899:280


Conservation Status


Last record: 1934

IUCN RedList status: Extinct



Santa Cruz (=Indefatigable), Galápagos Islands, Ecuador


Biology & Ecology




MCZ 27036 (skin and skull; female)
MCZ 27037 (skin and skull; female)






Original scientific description:

Thomas, Oldfield. (1899). Descriptions of new neotropical mammals. Ann. and Mag. Nat. Hist. ser. 7, v. 4, 1899, p. 280.


Other references:

Dowler, R.C., Caroll, D.S. and Edwards, C.W. 2000. Rediscovery of rodents (Genus Nesoryzomys) considered extinct in the Galápagos Islands. Oryx 34:109-117.

Dowler, R.C., Carroll, D.S., and Edwards, C.W. 2000. Rediscovery of rodents (Genus Nesoryzomys) considered extinct in the Galapagos Islands. Oryx 34(2): 109-117.

Freudenthal, M. and Martín-Suárez, E. (2013). Estimating body mass of fossil rodents. Scripta Geologica 145: 1-130. [0.083-0.129 kg estimate]

Goodwin, Harry A. and Goodwin, J. M. (1973). List of mammals which have become extinct or are possibly extinct since 1600. Int. Union Conserv. Nat. Occas. Pap. 8: 1-20.

Hopkins, S. B. (2008). Reassessing the mass of exceptionally large rodents using toothrow length and area as Proxies for body mass. Journal of Mammalogy 89, 1: 232-243.

Musser, G.G. and Carleton, M.D. 1993. Family Muridae. In: D.E. Wilson and D.A. Reeder (eds), Mammal species of the world: A taxonomic and geographic reference, pp. 501-736. Smithsonian Institution Press, Washington, DC, USA.

Musser, G.G. and Carleton, M.D. 2005. Superfamily Muroidea. In: D.E. Wilson and D.A. Reeder (eds), Mammal Species of the World: a geographic and taxonomic reference, pp. 894-1531. The John Hopkins University Press, Baltimore, USA.

Orr, R. T. (1938). A new rodent of the genus Nesoryzomys from the Galapagos Islands. Proceedings of the California Academy of Science, 4th Series, 23: 303-306.

Patton, J. L., and M. S. Hafner. 1983. Biosystematics of the native rodents of the Galapagos Archipelago, Ecuador. Pp. 539-568, in Patterns of evolution in Galapagos organisms (R. I. Bowman, M. Benson, and A. E. Leviton, eds.). American Association for the Advancement of Science, Pacific Division, San Francisco, CA, 568 pp.

Tirira, D., Dowler, R., Boada, C. and Weksler, M. (2008). Nesoryzomys indefessus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. ( Downloaded on 29 July 2013.

Tirira, D.G. & Weksler, M. 2019. Nesoryzomys indefessus. The IUCN Red List of Threatened Species 2019: e.T14708A22390443. Accessed on 20 June 2022.


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