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| Ctenomys uco Alvarado-Larios, Teta, Cuello, Jayat, Tarquino-Carbonell, D’Elía, Cornejo & Ojeda, 2024 |
Abstract
The genus Ctenomys Blainville, 1826 includes 68 living species of small to medium-sized (100–1200 g) caviomorph rodents of subterranean habits. During the last decade, this genus has been the subject of numerous taxonomic studies, including the description of new species and the proposal of novel synonyms. Based on phylogenetic analysis of mitochondrial DNA sequences and qualitative and quantitative morphological traits, here we review the species boundaries of the tuco-tucos of the species group of C. mendocinus and describe a new species. The new species is morphologically distinct from other phylogenetically and geographically close species of Ctenomys (e.g., C. fochi, C. mendocinus), showing several differences in their craniodental traits (e.g., proportionally longer nasals and less globose tympanic bullae). The new species occurs in montane grasslands and shrublands of northwestern Mendoza (ca. 2710 m a.s.l.) and in lowlands (ca. 1000 m a.s.l.) of the Monte Desert ecoregion in an area highly impacted by accelerated processes associated with the wine industry.
Keywords: Caviomorpha, Ctenomys fochi, Mendoza, Monte, Octodontoidea, Southern Andean steppe, tuco-tucos
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| Cranial anatomy of Ctenomys uco sp. nov. Lateral (above), dorsal (below, left), and ventral (below, right) views of the skull and labial view of the mandible (middle) of the holotype (CMI 7712). Scale = 5 mm. |
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| External appearance of Ctenomys uco sp. nov. A CMI 7712 (holotype), from Cajón de Arenales, Tunuyán, Mendoza, Argentina; B CMI 7737, from Finca Caicayén II, Tupungato, Mendoza, Argentina. |
Ctenomys uco sp. nov.
Morphological diagnosis: A small-sized tuco-tuco of the C. mendocinus species group (TOTL, 215–263 mm; TAIL, 64–79 mm; HFL, 31–36 mm: EAR, 6–8 mm; Weight, 109–138 g); dorsum Drab to Dusky Drab, which turns lighter on flanks; venter Light Brownish Drab to Light Drab, with line separating from dorsum scarcely defined; a patch above nose and forehead, blackish. Skull moderately robust, with rostrum and nasals proportionally long and narrow; premaxillary-frontal suture evident anterior to the naso-frontal suture; interorbital region with posteriorly divergent outer margins. Zygomatic arches thin, slightly divergent backwards in dorsal view; dorsal profile of cranium with a marked ventral inflection in the parietal-occipital region; incisive foramina short and narrow, recessed in a common fossa of posteriorly divergent outer borders; interpremaxillary foramen small or nearly absent; sphenopalatine vacuities nearly tear-shaped; auditory bullae moderately inflated and nearly oval, with salient auditory tubes.
Etymology: We named this species in reference to the region where the type locality lays, the Valle de Uco (Uco Valley), which includes the Tupungato, Tunuyán, and San Carlos Departments in Mendoza Province, central western Argentina; this valley is well known for its fine wines.
Raquel Alvarado-Larios, Pablo Teta, Pablo Cuello, J. Pablo Jayat, Andrea P. Tarquino-Carbonell, Guillermo D’Elía, Paula Cornejo and Agustina A. Ojeda. 2024. A New living Species of the Genus Ctenomys (Rodentia: Ctenomyidae) from central-western Argentina. Vertebrate Zoology. 74: 193-207. DOI: 10.3897/vz.74.e115242
