''Megaoryzomys curioi'', also known as the Galápagos giant rat, is an extinct species of

sigmodontine The rodent subfamily Sigmodontinae includes New World rats and mice, with at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species ...

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 lower jaws. About 40% of all mammal species are roden ...

, known only from

Santa Cruz Island Santa Cruz Island ( Spanish: ''Isla Santa Cruz'', Chumash: ''Limuw'') is located off the southwestern coast of Ventura, California, United States. It is the largest island in California and largest of the eight islands in the Channel Islands ...

in the

Galápagos Islands The Galápagos Islands ( es, Islas Galápagos) are an archipelago of volcanic islands in the Eastern Pacific, located around the Equator west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with ...

. It likely met its demise when European settlers introduced invasive species to the island. It is the only species in the genus ''Megaoryzomys''. Its relationships have historically been unclear; it has been placed in both

Oryzomyini Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of the family Cricetidae. It includes about 120 species in about thirty genera,Weksler et al., 2006, table 1 distributed from the eastern United States to the southernmost parts of ...

and Thomasomyini in the past. A 2020 study favoured placing it in the former on overall skull morphology.

References

* Sigmodontinae Mammals described in 1979 Endemic fauna of the Galápagos Islands Monotypic rodent genera {{Sigmodontinae-stub