Gyldenstolpe giant rice rat

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Gyldenstolpe giant rice rat
Gyldenstolpia fronto.jpg

Gyldenstolpe's giant rice rat ( Gyldenstolpia fronto )

Systematics
Family : Burrowers (Cricetidae)
Subfamily : Sigmodontinae
Oryzomyalia
Tribe : Akodontini
Genre : Gyldenstolpia
Type : Gyldenstolpe giant rice rat
Scientific name
Gyldenstolpia fronto
( Winge , 1887)

The Gyldenstolpe giant rice rat ( Gyldenstolpia fronto , Syn: Scapteromys fronto , Kunsia fronto ) is a possibly extinct rodent species from the root family (Cricetidae). It occurred in two subspecies in Brazil and Argentina . The nominate form Gyldenstolpia fronto fronto is only known to be fossilized from late Pleistocene deposits from the area of Lagoa Santa on the Rio das Velhas in the Brazilian state of Minas Gerais , where the remains of four specimens were found in the caves Lapa da Escrivânia No. 5 and Lapa da Serra das Abelhas were. This taxon was first described by Herluf Winge in 1887 as Scapteromys fronto on the basis of a skull from the collection of Peter Wilhelm Lund . The holotype and only specimen of Gyldenstolpia fronto chacoensis was collected in September 1896 by A. Ros on the Río de Oro in the northern Argentine province of Chaco , scientifically described in 1932 by Nils Carl Gustaf Fersen Gyldenstolpe as an independent species and in 1966 by Philip Hershkovitz under the name Kunsia fronto chacoensis classified as a subspecies.

features

Characteristics are only documented for the type specimen of the subspecies Gyldenstolpia fronto chacoensis . The head-trunk length is 225 mm, the tail length 110 mm, the ear length approximately 20 mm and the hind foot length 43 mm. The exact weight is unknown but is estimated to be around 150 g. estimated. The tail is relatively short. The fur is long and moderately soft. The fur hair on the upper side is ocher cinnamon brown, heavily interspersed with longer dark hair, especially on the middle of the back. The basic hair is slate-colored, the tips of the hair are blackish. The ears, the snout and the upper side of the front feet are hairy wood-brown and interspersed with light yellow-brown hair. The hind feet are more silver gray. The color of the underside is whitish or light gray and light yellow-brown or washed-out yellow. The basic hairs of the pleura and peritoneum are dark. The nasal mirror is framed in brown. The tail, the length of which is 50% or less of the length of the head and torso, is covered with bristle hairs that are brownish on top and lighter on the bottom. It is shorter in the distal direction than in the proximal direction with three hairs on each scale. The front and rear feet have long, strong claws, while those of the front feet are longer.

The skull of G. f. chacoensis is characterized by a U-shaped frontal suture, while the slightly smaller skull of G. f. fronto has a v-shaped nasal frontal suture. It is also characterized by a slightly pointed foremost bridge of the nose, a condition that G. f. fronto is unknown. The front edge of the zygomatic plates shows clear thorny processes, which in G. f. fronto are less noticeable. The frontal bone of G. f. chacoensis has sharp lateral edges, while G. f. fronto are smooth. The zygomatic-maxillary suture (sutura zygomaticomaxillaris) in G. f. chacoensis is currently, with G. f. fronto this state is not documented.

Habitat and way of life

The Gyldenstolpe giant rice rat inhabited wetlands dominated by bushes, wet savannahs, swamps, peat bogs and marshland. Nothing is known about their way of life.

status

The Gyldenstolpe giant rice rat was in 1996 in the endangered species red list of the IUCN added and "at risk" category ( vulnerable ) classified. In 2008, the status was "high risk" ( endangered ) and 2018 to "threatened with extinction" ( critically endangered ) with the addition "possibly extinct" ( possibly extinct ) changed. Since this species has not been seen alive since 1896, it must be assumed with a high degree of probability that it is already extinct.

literature

  • Herluf Winge: Jordfundne og nulevende gnavere (Rodentia) from Lagoa Santa, Minas Geraes, Brazil: med udsigt over gnavernes indbyrdes slægtskab. E. Museo Lundii, Copenhagen, 1 N ° 3, 1887, p. 44
  • Nils Gyldenstolpe: A new Scapteromys from Chaco Austral, Argentine. Arkiv för Zoologi, 24B (1), 1932, pp. 1-2
  • Philip Hershkovitz: South American Swamp and Fossorial rats of the Scapteromyine Group (Cricetinae, Huridae) with comments on the glans penis in Murid taxonomy. Journal of Mammals, Vol. 31 (2), 1966, pp. 112-122
  • Fernando Dias de Ávila-Pires : A new subspecies of Kunsia fronto (Winge, 1888) from Brazil (Rodentia, Cricetidae). Revista Brasileira de Biologia, 32, 1972, pp. 419-422
  • Osvaldo Reig : Genus Kunsia, Hershkovitz In: The evolutionary history of the South American cricetid rodents. Dissertation at the University of London , November 1972, pp. 295-301
  • Ulyses FJ Pardiñas, Guillermo D'Elía, Pablo Teta: Una introducción a los mayores sigmodontinos vivientes: revisión de Kunsia Hershkovitz, 1966 y descripción de un nuevo género (Rodentia: Cricetidae). Arquivos do Museu Nacional, Rio de Janeiro, vol. 66, no. 3-4, 2009, pp. 509-594
  • Ulyses FJ Pardiñas & Alexandra MR Bezerra: Genus Gyldenstolpia Pardinas, D'Elía & Teta, 2009 In: James L. Patton , Ulyses FJ Pardiñas, Guillermo D'Elía (eds.): Mammals of South America, Volume 2 - Rodents. The University of Chicago Press, Chicago, 2015, ISBN 978-0-226-16957-6 , pp. 222-225
  • Ulyses FJ Pardiñas, Dennisse Ruelas, Jorge Brito, Lisa Bradley, Robert Bradley, Nicté Ordóñez Garza, Boris Kryštufek , Joseph Cook, Erika Cuéllar Soto, Jorge Salazar-Bravo, Gregory Shenbrot , Elisandra Chiquito, Alexandre Percequillo, Joyce Prado, Rudolf Jim Patton, Livia León-Paniagua: Family Cricetidae (True Hamsters, Voles, Lemmings and New World Rats and Mice) In: Handbook of the Mammals of the World. Volume 7: Rodents II, Lynx Edicions, Barcelona 2017, ISBN 978-84-16728-04-6 , p. 459

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