Order Rodentia - Family Cricetidae 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 2 955 1189 book chapter 0-8018-8221-4 10.5281/zenodo.7316535 Sigmodon (Sigmodon) arizonae Mearns 1890 Sigmodon (Sigmodon) arizonae Mearns 1890 , Bull. Am. Mus . Nat. Hist., 2: 287 . Type Locality: USA , Arizona , Yavapai Co., 3 mi ( 5 km ) SE Camp Verde, Bell’s Ranch (as restricted by Hoffmeister, 1986 ). Vernacular Names: Arizona Cotton Rat . Synonyms: Sigmodon (Sigmodon) cienegae A. B. Howell 1919 ; Sigmodon (Sigmodon) jacksoni Goldman 1918 ; Sigmodon (Sigmodon) major Bailey 1902 ; Sigmodon (Sigmodon) plenus Goldman 1928 . Distribution: Extreme SE California , SC Arizona , and extreme SW New Mexico , USA ; south along coastal plain and adjoining foothills, sea level- 1900 m, in W México to S Nayarit . Conservation: IUCN – Extinct as S. a. arizonae , Lower Risk (nt) as S. a. plenus , otherwise Lower Risk (lc). Discussion: Subgenus Sigmodon , S. hispidus species group. Zimmerman (1970) recognized the chromosomal and morphological differences that support the specific separation of S. arizonae from S. hispidus , under which it had been arranged as a subspecies ( Bailey, 1902 ; Mearns, 1890). Distribution and differentiating traits amplified by Severinghaus and Hoffmeister (1978) , Elder and Lee (1985) , Hoffmeister (1986) , Carleton et al. (1999), and Frey et al. (2002) . Association of jacksoni , known only by the type specimen, as a junior synonym has been questioned (Carleton et al., 1999; Hoffmeister, 1986 ). Hall (1981) retained all named forms as subspecies, a classificatory formality unwarranted without fresh studies of populational variation across the species’ range. Probable sister species of S. mascotensis according to a variety of data (Carleton et al., 1999; Elder, 1980 ; Peppers and Bradley, 2000 ; Peppers et al., 2002 ; Zimmerman, 1970 ).