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| [B, D] Oreoryzomys huancabambensis sp. nov. Llancachahua-Tarqui, Ruelas, Escobar & Pacheco, [A, E] Oreoryzomys balneator (Thomas, 1900) in Llancachahua-Tarqui, Ruelas, Escobar et Pacheco Torres, 2025. |
Abstract
Oreoryzomys is a monotypic genus represented solely by Oreoryzomys balneator and has long been considered enigmatic due to the scarce information available since its description more than a century ago. In this study, we present a systematic revision of O. balneator with an integrative approach, focusing on Peruvian populations. We analyzed 73 specimens using morphological methods, complemented with phylogenetic analyses based on two mitochondrial genes. Our results reveal that the Peruvian populations previously referred as O. balneator represent a new and unnamed species. This species is genetically and morphologically differentiated, and geographically isolated from O. balneator sensu stricto (from Tungurahua Province, the type locality) and from the western Ecuadorian populations of El Oro Province. We formally describe this new species which inhabits montane forests from southeastern Ecuador (Zamora Chinchipe Province) to northeastern Peru (Piura and Cajamarca departments), at elevations between 1520 to 2990 m a.s.l. This work represents the first systematic revision of this genus, providing novel insights into its phylogenetic relationships, distribution, and natural history.
Keywords: Andes, Huancabamba Depression, Oryzomyini, Piura Department, Yungas
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| External comparisons between Oreoryzomys balneator (AMNH 67569, A, C, E) and Oreoryzomys huancabambensis sp. nov. (MUSM 10701, B, D, F). |
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| Live specimen of Oreoryzomys huancabambensis sp. nov. (MUSM 55512, holotype) from Habaspite, Carmen de la Frontera, Piura Department. Note the presence of three commensal staphylinid beetles on the head of the specimen. Photograph taken by Víctor Pacheco. |
Oreoryzomys huancabambensis sp. nov.
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| A) Panoramic view of the type locality of Oreoryzomys huancabambensis sp. nov. in Habaspite, Carmen de la Frontera Province, Piura Department, in 2021. B) Typical habitats within forest patches, and C) low-scale mining activities in the type locality. Photographs taken by Víctor Pacheco. |
Daniel Llancachahua-Tarqui, Dennisse Ruelas, Elizabeth Escobar and Víctor Raúl Pacheco Torres. 2025. Introduction to the Systematics of Oreoryzomys balneator (Rodentia; Cricetidae) with the Description of A New Species from Peruvian montane forests. Revista peruana de biología. 32(4): e31354. DOI: doi.org/10.15381/rpb.v32i4.31354
