461 ACTA ZOOLOGICA BULGARICA Acta zool. bulg., 66 (4), 2014: 461-468 * Corresponding author: Mohammadi.zeinal@gmail.com Systematics and Phylogenetics Research Article Introduction The Eastern broad-toothed ield mouse Apodemus mystacinus (Danford and Alston, 1877) was original- ly described as Mus mystacinus from Zebil, Bulgar Dagh, southern Turkey. This species is distributed in the Eastern Mediterranean through Anatolia, the Levant and the northern part of Iraq. Its range also extends westward to some Aegean islands and the easternmost boundary of its range is known to be North Iraq. It occurs in the South Caucaususin Georgia (Corbet 1978, Musser, Carleton 2005). A. mystacinus was accounted from morphological point of view as the most primitive species of the ge- nus Apodemus (ellerMan, Morrison-sCott 1951). It was also recognised as the ancestral member of the subgenus Sylvaemus in the Western Palaearctic based on molecular phylogeny (CheloMina, atopkin 2010). However, the inclusion of A. mystacinus in the subgenus Sylvaemus was not accepted by some authors (Çolak et al. 2007). Mezhzherin (1997) and pavlinov et al. (1995) assigned this species to the subgenus Karstomys as a member of the genus Sylvaemus. ellerMan, Morrison-sCott (1951) revised the taxonomic status of the subspecies of A. mystacinus and accepted two valid subspecies: A. m. mystacinus and A. m. euxinus. v ohralik et al. (2002) considered the Asian populations of A. mystacinus as a homoge- nous species based on colouration and morphometric analyses, with no distinct subspecies. A. m. mystaci- nus and A. m. euxinus were validated by Colak et al. (2004). The related form occurring in the Balkan Peninsula A. epimelas Nehring, 1902 has been syn- onymised with A. mystacinus or recognised as its subspecies (ellerMan 1941, ellerMan, Morrison- Morphological Morphometric Characterisation of the Eastern Broad-toothed Field Mouse Apodemus mystacinus (Rodentia: Muridae) from Zagros Mountains, north-western Iran Jamshid Darvish 1,2 , Zeinolabedin Mohammadi 1* , Fatemeh Ghorbani 1 , Ehsan Mostafavi 3,4 1 Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran; E-mail: Mohammadi.zeinal@gmail.com 2 Applied Animal Institute, Rodentology Research Department, Ferdowsi University of Mashhad, Mashhad, Iran 3 Department of Epidemiology, Pasteur Institute of Iran, Tehran, Iran 4 Research Centre for Emerging and Reemerging infectious diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran Abstract: The eastern broad-toothed ield mouse Apodemus mystacinus (Danford and Alston, 1877) has been re- ported from the Levant, some Aegean islands, Anatolia, the southern Caucasus and North Iraq. In this study, 15 specimens of A. mystacinus were recorded from the Zagros Mountains, north-western Iran. Four external features, 13 linear measurements of the skull and 14 dental characters were measured. Dental and cranial characters were evaluated based on the frequencies of 27 character states for 12 morphological characters. The oak forests of the north-western slopes of the Zagros Mountains are known as the eastern- most range boundary of A. mystacinus, and the species has been blocked by the north-south extension of the Zagros Mountains. Based on morphological and morphometric characters, we suggest that the popu- lation of A. mystacinus from the Zagros Mountains possibly belongs to a new subspecies but this issue requires further analyses. Keywords: Apodemus mystacinus, Zagros Mountains, morphometrics, Iran, subspecies