A new species of the tetraploid vizcacha rat Tympanoctomys (Caviomorpha, Octodontidae) from Central Patagonia, Argentina

A new living species of the desert-adapted tetraploid rodent Tympanoctomys (Caviomorpha, Octodontidae) is described. The new form is restricted to the type locality in Chubut Province, central Patagonia, Argentina, although is known from at least 4 additional Holocene-aged localities along the middl...

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Detalles Bibliográficos
Autores: Teta, Pablo Vicente, Pardiñas, Ulises Francisco J., Udrizar Sauthier, Daniel Edgardo, Gallardo, Milton H.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/22721
Acceso en línea:http://hdl.handle.net/11336/22721
Access Level:acceso abierto
Palabra clave:Pipanacoctomys
Salinoctomys
Octodontids
Taxonomy
Chubut
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:A new living species of the desert-adapted tetraploid rodent Tympanoctomys (Caviomorpha, Octodontidae) is described. The new form is restricted to the type locality in Chubut Province, central Patagonia, Argentina, although is known from at least 4 additional Holocene-aged localities along the middle and lower valley of the Chubut River. Tympanoctomys sp. nov. is smaller than the living T. barrerae, its general coloration is yellowish (reddish in T. barrerae ) and its tail is equal to ~ 43–50% of head and body length (~49–53% in T. barrerae). Its skull and dentition are characterized by a unique combination of morphological traits, including narrow and posteriorly acuminate nasals (broad and barrel-shaped in T. barrerae ), supraoccipital not laterally expanded (expanded in T. barrerae), and 8-shaped lower 3rd molar (comma-shaped in T. barrerae and † T. cordubensis). Morphometric and genetic evidence supports the specific distinction of this Patagonian endemic Tympanoctomys, also characterized by smaller sperm than T. barrerae . The reduced range of the new species, coupled with its recent extinction from the Chubut River valley and the potential impact of large uranium mining projects in central Patagonia, suggest that this species faces a severe extinction risk in the short term.