Order Rodentia - Family Ctenomyidae Author Wilson, Don E. Author Reeder, DeeAnn text 2005 The Johns Hopkins University Press Baltimore Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2 1560 1570 book chapter 0-8018-8221-4 10.5281/zenodo.7316535 Ctenomys dorbignyi Contreras and Contreras 1984 Ctenomys dorbignyi Contreras and Contreras 1984 , Hist. Nat., 4 (13): 131 . Type Locality: Argentina , Prov. Corrientes , Dept. Berón de Astrada, Paraje Mbarigüí ( 27 ^o 33’S , 57 ^o 31’W ) . Vernacular Names: D'Orbigny's Tuco-tuco . Distribution: Prov. Corrientes ( Argentina ). Discussion: See Contreras and Scolaro (1986) for details of geographic distribution. Karyotype has 2n=70 and FN=84 ( Ortells et al., 1990 ) but Garcia et al. (2000) reported a FN=88. The karyotype of dorbignyi is indistinguishable from some of the karyotypes assigned to C. pearsoni in gross morphology ( Ortells et al., 1990 ) and G-band patterns ( Garcia et al., 2000 ). Garcia et al. (2000) reported differences in the C-bands of the two species but results for dorbignyi are different from that reported by Reig et al. (1992) . Phylogenetic analysis of chromosomal characters indicates that dorbignyi is paraphyletic within pearsoni and Garcia et al. (2000) concluded that there are insufficient cytogenetic data to consider dorbignyi distinct from pearsoni . The problem is that several distinct karyotypes from different localities have been reported or associated with pearsoni , none of which can be associated with specimens from the type locality (see comments under pearsoni ). Although there may be insufficient cytogenetic data to consider dorbignyi distinct from populations of pearsoni with a 2n=70, Novello and Lessa (1986) have suggested that more than a single species was represented among populations of pearsoni . Without knowledge of which karyotype is associated with the specimens from the type locality of pearsoni it is not possible to determine whether dorbignyi represents one of the chromosomally differentiated species within the pearsoni complex or should be placed in synonomy with pearsoni . Little or no differentiation of isozymes was observed among dorbignyi , perrensi , and roigi ( Ortells and Barrantes, 1994 ) and all four of these species have symmetric sperm ( Vitullo et al., 1988 ) and a glans penis with pairs of spiny bulbs ( Balbontin et al., 1996 ).