Microtus elbeyli, Yiğit & Çolak & Sözen, 2016
|
publication ID |
https://doi.org/ 10.3906/zoo-1404-19 |
|
persistent identifier |
https://treatment.plazi.org/id/03F8878D-FF8C-E45E-FFC3-8EB49F81F1A0 |
|
treatment provided by |
Felipe |
|
scientific name |
Microtus elbeyli |
| status |
sp. nov. |
Microtus elbeyli sp. nov.
Holotype: An adult male (collection number: 2919) held in the Zoology Museum of the Biology Department at Ankara University.
Type locality: 1 km NW of Karacaören village of Kilis Province in southeastern Turkey.
Diagnosis: External measurements (mm) and weight (g) of holotype; TbL = 135, TL = 21, HfL = 18, EL = 12, and W = 36. Some cranial measurements (mm) of holotype: occipitonasal length is 27.6, zygomatic breadth 16.5, basal length 25, nasal length 7.7, width of braincase 12.16, height of braincase with bullae 10.4, diastema length 9.0, palatal length 14.6, mandible length 16.86 ( Table 1). The dorsal color is generally ochreous and slightly paler on sides. Ventral fur is pale buff with dark gray bases. There is a prominent delineation line between flanks and belly. Upper and ventral hair of feet are pale buff. The skull is slender with comparatively smooth brain case ( Figure 2 View Figure 2 ). M 2 in all specimens was found to be the agrestis morphotype. The diploid number of chromosomes is 46 with 50 chromosomal arms.
Etymology: Elbeyli is a town of Kilis Province where most of the specimens were collected.
Description: The 15 examined specimens with 2n = 46 and ochreous dorsal color were captured from two different locations in southeastern Turkey ( Figure 1 View Figure 1 ). However, the dorsal pelage was found to be exceptionally dark brownish in a few specimens. The dorsal colors of our specimens were markedly different from M. guentheri but slightly different from M. cfr. irani with 2n = 60 from Mardin. The external and cranial measurements and some morphological structures of specimens were drawn and given in our previous work (Çolak et al., 1997). The skull structures of these new specimens have some differences from M. cfr. irani and M. guentheri . Even though the skull is similar to that of M. guentheri , the sharp slope of the supraoccipital region in the braincase and mandible morphology are the main differences ( Figure 2 View Figure 2 ). The braincase is smoother than those of M. guentheri and M. cfr. irani and is not shallow as in M. socialis . Apart from these differences, the nasal area in M. guentheri is markedly bent down compared to the other two species. The parietal bones of M. irani are narrow and exo-occipital condyles are almost visible in the dorsal aspect of skull. Incisive foramina do not project beyond the M 1. The ventral parts of tympanic bullae are enlarged and are more marked than in M. socialis but are almost similar to those of M. guentheri . The mandible is slender and its coronoid and angular processes are different from other species in the manner of markedly separating the coronoid process from the condyloid process. The skull is slender with a comparatively smooth brain case and the suprameatal triangle is markedly a more rounded oval than in the other species.
Dentition: The occlusal molar patterns of M 2 are found to be the non-agrestis morphotype and M 3 patterns were observed as 50% normal, 29% complex, and 21% duplicate forms ( Figure 3 View Figure 3 ). M 2 patterns of all other specimens of M. guentheri and M. cfr. irani were found to be the non-agrestis morphotype; therefore, it was concluded that M 2 patterns are not distinctive among taxa. Kefelioğlu (1995) reported 40% non-agrestis morphotype for M. socialis in Turkey. Similarly, the agrestis morphotype was observed in high frequencies in M. socialis specimens of Turkish, Caucasian, Lebanese, Syrian, and Iranian origin ( Kefelioğlu and Kryštufek, 1999; Kryštufek and Kefelioğlu, 2001a). In the type specimen of M. irani , the M 2 occlusal molar pattern was also reported as the agrestis morphotype in the figure given by Kryštufek and Kefelioğlu (2001b).
Taxonomic remarks: According to morphological and karyological examinations of the specimens captured from southeastern Anatolia and its adjacent locations, it was determined that four species ( M. socialis , M. guentheri , M. cfr. Irani , and M. elbeyli sp. nov.) are distributed in the area ( Figure 1 View Figure 1 ). The habitat preference of M. guentheri was found to be different as indicated by Çolak et al. (1997), Yiğit and Çolak (2002), and Yiğit et al. (2012). The other two species ( M. elbeyli sp. nov. and M. cfr. irani ) are usually captured in the same type of habitat (semidry grain fields and steppe), but no sympatric occurrence was determined. Kryštufek and Kefelioğlu (2001b) stated that M. irani has pale and sandy buff dorsal color and also pointed out the cranial differences between the type series of M. irani and other Iranian specimens of M. irani such as bullae lengths, the zygomatic arches, and the incisive foramina. They also suggested that M. irani is an independent species known solely from its type locality. Astonishingly, Kryštufek et al. (2009, 2010) extended M. irani ’s distribution to the Mediterranean coast of southern Turkey ( Figure 1 View Figure 1 ), describing a new subspecies, Microtus irani karamani , based on phylogenetic analyses of social vole specimens.
Karyology: The karyotype of five specimens from the Microtus population in 2n = 46 from Kilis was described by Çolak et al. (1997) as 2n = 46, NF = 50, and NFa = 46. The X chromosome was large metacentric and the Y chromosome was the smallest metacentric ( Figure 4 View Figure 4 ) .
In the phylogenetic analyses of Kryštufek et al. (2009), M. anatolicus with 2n = 60, M. irani with 2n = 60, and M. socialis with 2n = 62 were grouped into the same cluster, indicating the close genetic resemblance. In our previous study (Yiğit et al., 2006), the specimens with 2n = 60 were also found and identified as Microtus schidlovskii in eastern Turkey, and we also pointed out the cranial similarities between M. schidlovskii and M. socialis . Even though the three taxa have the same karyotype (2n = 60), M. anatolicus and M. schidlovskii have more marked distinctive cranial peculiarities than those of M. cfr. irani ( Kefelioğlu and Kryštufek, 1999; Kryštufek and Kefelioğlu, 2001b; Yiğit et al., 2006b; Kryštufek et al., 2009, 2010). However, the karyotypes of M. irani were reported to be 2n = 60 and 64 by Zima and Kral (1984) and 2n = 62 by Golenishchev et al. (2002), and these findings emphasize the current taxonomic conflict between M. irani and M. cfr. irani ( Table 2).
The morphological examinations of our specimens indicate the cryptic differences in the dorsal coloration between M. elbeyli sp. nov. (previously identified as M. irani by Çolak et al., 1997) and M. cfr. irani (Mardin specimens); the first is ochreous and the second cinnamon buff in dorsal colorations. M. elbeyli sp. nov. also karyologically differs from M. cfr. irani recorded at Balkusan (Ermenek) by Kryštufek et al. (2009). Apart from these, the specimens (N = 3) captured around Mardin Province with 2n = 60 were identified as M. cfr. irani and have different skull structures with curved braincase with ventrally enlarged bullae rather than typical smooth and shallow braincase of Anatolian specimens of M. socialis . M. cfr. irani recorded from Balkusan (Ermenek) was also reported to be different from the type series of true M. irani from Shiraz ( Iran) (Kryštufek et al., 2009, 2010). However, the cranial peculiarities of the Mardin specimens are consistent with the given characteristics of M. cfr. irani by Kryštufek et al. (2009) and support the idea of its cryptic distribution through southeastern Anatolia to the west. Thus, this taxon also needs further investigation for taxonomic confirmation or to be assigned to another new species.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.