Mammalia 2016; aop *Corresponding author: Jamshid Darvish, Faculty of Science, Department of Biology, Ferdowsi University of Mashhad, Mashhad, Iran; Institute of Applied Zoology, Faculty of Science, Rodentology Research Department, Ferdowsi University of Mashhad, Mashhad, Iran; and Institute of Applied Zoology, Faculty of Sciences, Zoological Innovations Research Department, Ferdowsi University of Mashhad, Mashhad, Iran, e-mail: darvish_j2001@yahoo.com Safie Akbarirad: Faculty of Science, Department of Biology, Ferdowsi University of Mashhad, Mashhad, Iran Mansour Aliabadian: Faculty of Science, Department of Biology, Ferdowsi University of Mashhad, Mashhad, Iran; and Institute of Applied Zoology, Faculty of Sciences, Zoological Innovations Research Department, Ferdowsi University of Mashhad, Mashhad, Iran Safie Akbarirad, Jamshid Darvish* and Mansour Aliabadian Increased species diversity of brush-tailed mice, genus Calomyscus (Calomyscidae, Rodentia), in the Zagros Mountains, western Iran DOI 10.1515/mammalia-2014-0162 Received October 29, 2014; accepted October 9, 2015 Abstract: Two species of the brush-tailed mice (family Calomyscidae) have been identified in western Iran: Calo- myscus bailwardi and Calomyscus urartensis. Three sepa- rate karyotypes have been recorded for samples allocated to C. bailwardi; however, no formal taxonomic review of these entities has yet been carried out. Herein, molecular, morphometric, and geometric-morphometric analyses are utilized to assess the distinctness of Calomyscus samples from the Zagros Mountains in western Iran, delineating three distinct evolutionary units that may deserve spe- cies status other than C. bailwardi, in two different genetic clades. These four taxa within the Zagros folded belt – (A) C. bailwardi, from the type locality and its vicinity; (B) C. cf. bailwardi, from the southeastern part of the Zagros chain; (C) specimens from Songhor in Kermanshah Province; and (D) specimens from Saghez in Kurdistan Province- are supported by the analysis of two mitochondrial gene sequences. Both traditional morphometrics of cranioden- tal traits and geometric-morphometrics of the cranium and mandible confirmed that samples C and D were dis- tinctive groups, both readily separable from C. bailwardi. Our results show that the Zagros Mountains in Iran have a high species diversity due to a complex topography that has promoted geographic isolation in the genus. Keywords: brush-tailed mouse; Calomyscus bailwardi; mtDNA; Zagros Mountains. Introduction The taxonomic rank of Calomyscus Thomas, 1905 (the brush-tailed mice) within the broader group of muroid rodents as well as the number of species contained within the genus has been debated since its first description by Thomas (1905). The genus has been placed as a mono- typic tribe, Calomyscini, within the family Cricetidae (Vorontsov and Potapova 1979) and as a member of the Gerbillidae (particularly the subfamily Myocricetodon- tinae; Wessels 1996, but also see Krystufek and Vohralik 2009). However, Musser and Carleton (1993) elevated the genus to a subfamily and then Musser and Carleton (2005) elevated it to a monotypic family on both morphological and molecular grounds. Some morphological characters which diagnose the family Calomyscidae relative to other members of Cricetidae include the combination of (a) tail length being longer than head and body, (b) well-furred tail forming a terminal brush, (c) five asymmetric tuber- cles on the upper and lower first molars, and (d) lack of cheek pouches (Vorontsov and Potapova 1979). Molecular phylogenetic analyses determined the posi- tion of Calomyscidae as an isolated lineage in Muroidea, but its relationship with other family of muroid has been uncertain (Jansa and Weksler 2004; Steppan et al. 2004). Nevertheless, Schenk et al. (2013) (also Michaux et al. 2001 with slight support) placed the family at the base of the large clade of Eumuroida (sensu Steppan et al. 2004) that, otherwise, contains Nesomyidae, Cricetidae and Muridae. The family Calomyscidae is monotypic, and the single genus Calomyscus has both a restricted geographical distri- bution in west-central Asia and a high degree of morpho- logical similarity among the defined species. In the most recent compilation, Musser and Carleton (2005) recognized eight species, listing three additional names as synonyms. The first species described was Calomyscus bailwardi Thomas, 1905, the type species of Thomas’s genus. There is substantial karyotypic diversity within the genus, with diploid numbers ranging from 30 to 52, and autosomal fundamental numbers between 42 and 60 (Vorontsov et al. 1979; Meyer and Malikov 1995, 2000; Malikov et al. 1999; Bereitgestellt von | De Gruyter / TCS Angemeldet Heruntergeladen am | 04.02.16 09:24