Nannospalax xanthodon Nordmann, 1840

Kankiliç, Teoman, Kankiliç, Tolga, Ozan, Perinçek Seçkin, Şeker, Ozan & Kivanç, Erkut, 2014, Morphological and biometrical comparisons of the baculum in the genus Nannospalax Palmer, 1903 (Rodentia: Spalacidae) from Turkey with consideration of its taxonomic importance, Turkish Journal of Zoology 38 (2), pp. 144-157 : 151

3.3. The baculum characteristics of Nannospalax xanthodon Nordmann, 1840

This species generally included populations from western Turkey and had the lowest diploid chromosome values. The chromosomal races within this species mostly consisted of small and isolated populations. The bacula of this species were generally longer (6.43 mm) than those of the other species. This species had no distal openings in the bacula, such as those that were found in the species N. labaumei , the functions of which are unknown.

Distally, the baculum had an incision between the 2 lateral parts and was extremely dorsoventrally flattened. When the length of the baculum was taken into account, it was much shorter distally than proximally. Most of the samples were slanted dorsoventrally. Variations in the shape of the proximal part of the baculum were not detected in this species. The baculum gradually narrowed proximally and was smooth at the tip. Although the structures of the baculum were generally similar within this species, noticeable differences were observed among the different chromosomal races. The most curved bacula were found in the 2n = 40 and the 2n = 52 chromosomal races of this species, with angles of 134.6° and 139.9°, respectively. The longest baculum occurred in the samples of the 2n = 36 chromosomal race (7.81 mm) ( Table 2; Figure 2 ). Proximally, the width of the baculum was approximately equal to that of the distal part in the 2n = 36 chromosomal race. The narrowest region of the baculum was the discoid part ( Figure 5 ). Additionally, the samples with the widest discoid part were found in the 2n = 36 chromosomal race (0.581 mm).

Figures

Figure 2. Morphometric variation among the species of the 6 measurements taken from the baculum.

Figure 5. Different baculum types of 3 species (N. xanthodon, N. ehrenbergi, and N. leucodon) in dorsal, lateral, and ventral view, respectively.