Sigmodon Say and Ord 1825

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Cricetidae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 955-1189 : 1173

Sigmodon Say and Ord 1825

Sigmodon Say and Ord 1825 , J. Acad. Nat. Sci. Philadelphia, 4 (2): 352.

Type Species: Sigmodon hispidus Say and Ord 1825

Synonyms: Deilemys Saussure 1860 ; Lasiomys Burmeister 1854 .

Species and subspecies: 14 species in 2 subgenera:

Subgenus Sigmodon (Sigmodon) Say and Ord 1825

Subgenus Sigmodon (Sigmomys) Thomas 1901

Species Sigmodon (Sigmodon) alleni Bailey 1902

Species Sigmodon (Sigmomys) alstoni Thomas 1880

Species Sigmodon (Sigmodon) arizonae Mearns 1890

Species Sigmodon (Sigmodon) fulviventer J. A. Allen 1889

Species Sigmodon (Sigmodon) hirsutus Burmeister 1854

Species Sigmodon (Sigmodon) hispidus Say and Ord 1825

Species Sigmodon (Sigmodon) inopinatus Anthony 1924

Species Sigmodon (Sigmodon) leucotis Bailey 1902

Species Sigmodon (Sigmodon) mascotensis J. A. Allen 1897

Species Sigmodon (Sigmodon) ochrognathus Bailey 1902

Species Sigmodon (Sigmodon) peruanus J. A. Allen 1897

Species Sigmodon (Sigmodon) planifrons Nelson and Goldman 1933

Species Sigmodon (Sigmodon) toltecus Saussure 1860

Species Sigmodon (Sigmodon) zanjonensis Goodwin 1932

Discussion: Sigmodontini . Hershkovitz (1955 a) arranged Sigmodon with Holochilus , Neotomys , and Reithrodon as the sigmodont group, but other evidence has eroded the tribal-level affinity of each to Sigmodon (see those generic accounts) and leaves the genus as the sole living tribal member. Cladistic isolation from other sigmodontine genera, typically as a basal lineage, affirmed in broad taxonomic surveys of phallic morphology ( Hooper and Musser, 1964 a) and mitochondrial genes (D’Elía et al., 2003; Engel et al., 1998; Smith and Patton, 1999). Ambiguous evidence for geographic origin, North versus South America, discussed by Voss (1992) and Peppers et al. (2002).

Sigmomys , type species Sigmodon alstoni , has been variously treated as a distinct genus ( Ellerman, 1941; Gyldenstolpe, 1932; Handley, 1976), a subgenus of Sigmodon ( Husson, 1978) , or a full synonym (Cabrera, 1961; Hershkovitz, 1955 a; Voss, 1992). Peppers et al. (2002) discussed the possible recognition of alstoni within a monotypic genus, subgenus, or simply species group; in view of its morphological distinctiveness ( Voss, 1992) and cladistic dichotomy relative to all other Sigmodon species ( Peppers et al., 2002), the formal rank of subgenus seems appropriate.

North American forms revised by Bailey (1902), with subsequent partial revisions by Baker (1969), Zimmerman (1970), Voss (1992), Carleton et al. (1999), and Peppers and Bradley (2000); further alpha-taxonomic study dearly needed. Standard karyology summarized by Zimmerman (1970) and Carleton et al. (1999); banded karyotypes by Elder (1980) and Elder and Lee (1985); albumin differentiation by Fuller et al. (1984); and mitochondrial DNA variation by Peppers and Bradley (2000) and Peppers et al. (2002). Skin-and-skull morphology ( Baker, 1969; Bailey, 1902), karyology ( Elder and Lee, 1985; Zimmerman, 1970), and molecular data ( Peppers et al., 2002) have yielded conflicting pictures of species-group associations. Species groups observed here follow the last study, which broadly treats most species under the revised understanding of S. hispidus .