Pere Mıquel PARÉS-CASANOVA, Abu Bakar SIDDIQ, Vedat ONAR

Cranial size and shape sexual dimorphism in the Kangal dog from Turkey

This study has so far been the first attempt to characterize and quantify skull sexual variation in Kangal dog, by means of geometric morphometric techniques. A sample of 16 adult Kangal crania has been analyzed with this purpose. To obtain a full image of morphological pattern, digital pictures were taken from the ventral, left lateral, and dorsal sides of each skull, and a total of 16, 15, and 16 landmarks respectively were obtained on each image. Skull size and shape differed significantly in all aspects among different sexes, male skulls being bigger. Shape differences were observed mainly on zygomatic arch and muzzle on the dorsal view, pterygoid bone and articular surface to mandibular condyle in the lateral aspect, and cranial width and maxillary bone on the ventral view. Although the sample was comparatively small in number, being the first geometric morphometric approach applied on the Kangal dog, the obtained results will add vital information particularly to understand the cranial shape sexual dimorphism of this unique dog breed in Turkey.

Keywords:

Geometric morphometrics, sexual dimorphism skull morphometry, Kangal dog, Turkey,

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1. Evans HE, de Lahunta A. Miller’s Anatomy of the Dog. China: Elsevier, 2013.
2. Thuller MAO, Jangarelli M, do Couto DM, Araújo AHB. Sexual dimorphism of labrador retriever dogs by morphometry. Bioscience Journal 2015; 31 (5): 1475-1487. doi: 10.14393/BJv31n5a2015-26496
3. Abdel-Rahman EH, Taylor PJ, Contrafatto G, Lamb JM, Bloomer P et al. Geometric craniometric analysis of sexual dimorphism and ontogenetic variation: A case study based on two geographically disparate species, Aethomys ineptus from southern Africa and Arvicanthis niloticus from Sudan (Rodentia: Muridae). Mammalian Biology 2009; 74 (5): 361- 373. doi: 10.1016/j.mambio.2008.06.002
4. Bidau CJ, Martinez PA. Sexual size dimorphism and Rensch’s rule in Canidae. Biological Journal of the Linnean Society 2016; 119 (4): 816-830. doi: 10.1111/bij.12848
5. Yazdi FT, Alhajeri BH. Sexual dimorphism, allometry, and interspecific variation in the cranial morphology of seven Meriones species (Gerbillinae, Rodentia). Hystrix, the Italian Journal of Mammalogy 2018; 29 (2): 162-167. doi: 10.4404/ hystrix-00018-2017
6. Brehm VH, Loeffler K, Komeyli H. Schädelformen beim Hund. Anatomia, Histologia, Embryologia 1985; 14 (4): 324-331 (in German). doi: 10.1111/j.1439-0264.1985.tb00828.x
7. Onar V. A morphometric study on the skull of the German shepherd dog (Alsatian). Anatomia, Histologia, Embryologia 1999; 28 (4): 253-256. doi: 10.1046/j.1439-0264.1999.00202.x
8. Onar V, Özcan S, Pazvant G. Skull typology of adult male Kangal dogs. Anatomia, Histologia, Embryologia 2001; 30 (1): 41-48. doi: 10.1046/j.1439-0264.2001.00292.x
9. Drake AG, Klingenberg CP. Large‐scale diversification of skull shape in domestic dogs: disparity and modularity. The American Naturalist 2010; 175 (3): 289-301. doi: 10.1086/650372
10. Onar V, Cakirlar C, Janeczek M, Kiziltan Z. Skull typology of Byzantine dogs from the Theodosius Harbour at Yenikapı, Istanbul. Anatomia, Histologia, Embryologia 2012; 41 (5): 341- 352. doi: 10.1111/j.1439-0264.2012.01143.x
11. Andrews K, Lowe J, McCormick WD. Skull morphology of the domestic dog in relation to cephalic index. 69th AVTRW Annual Conference, London, UK: Royal Veterinary College; 2015.
12. Igado OO. Skull typology and morphometrics of the Nigerian local dog (Canis lupus familiaris). Nigerian Journal of Physiological Sciences 2017; 32 (2): 153-158.
13. Mitteroecker P, Gunz P. Advances in geometric morphometrics. Evolutionary Biology 2009; 36 (2): 235-247. doi: 10.1007/ s11692-009-9055-x
14. Adams DC. Methods for shape analysis of landmark data from articulated structures. Evolutionary Ecology Research 1999; 1 (8): 959-970.
15. Adams DC, Rohlf FJ, Slice DE. A field comes of age: geometric morphometrics in the 21st century. Hystrix, the Italian Journal of Mammalogy 2013; 24 (1): 7-14. doi: 10.4404/ hystrix-24.1-6283
16. Benítez HA. Sexual dimorphism using geometric morphometric approach. In: Moriyama H (ed.). Sexual Dimorphism. London, UK: IntechOpen Limited; 2013, pp. 35-50. doi: 10.5772/55195
17. Onar V, Siddiq AB, Asal R, Parés-Casanova PM. Craneometric canine types are well expressed at the level of the zygomatic arch conformation. International Journal of Morphology 2020; 38 (1): 78-82 (in Spanish with an abstract in English).
18. Rohlf FJ. The tps series of software. Hystrix, the Italian Journal of Mammalogy 2015; 26 (1): 9-12. doi: 10.4404/ hystrix-26.1-11264
19. Von den Driesch A. A Guide to the Measurement of Animal Bones from Archaeological Sites. Boston, MA, USA: Peabody Museum of Archaeology and Ethnology Harvard University; 1976.
20. Klingenberg CP. Analyzing fluctuating asymmetry with geometric morphometrics: concepts, methods, and applications. Symmetry 2015; 7 (2): 843-934. doi: 10.3390/ sym7020843
21. Zelditch ML, Swiderski DL, Sheets HD. Geometric Morphometrics for Biologists: A Primer. Boston, MA, USA: Elsevier Academic Press; 2004.
22. Rohlf FJ, Bookstein FL (eds). Proceedings of the Michigan Morphometrics Workshop. Special Publication No. 2, Michigan, MI, USA: The University of Michigan Museum of Zoology; 1990.
23. Klingenberg CP. MorphoJ: An integrated software package for geometric morphometrics. Molecular Ecology Resources 2011; 11 (2): 353-357. doi: 10.1111/j.1755-0998.2010.02924.x
24. Hammer Ø, Harper DAT, Ryan PD. Past: paleontological statistics software package for education and data analysis. Palaeontologia Electronica 2001; 4 (1): 1-9. https://palaeoelectronica.org/2001_1/past/past.pdf
25. Dale J, Dunn PO, Figuerola J, Lislevand T, Székely T, Whittingham LA. Sexual selection explains Rensch’s rule of allometry for sexual size dimorphism. Proceedings of the Royal Society B: Biological Sciences 2007; 274 (1628): 2971- 2979. doi: 10.1098/rspb.2007.1043
26. Van Damme R, Entin P, Vanhooydonck B, Herrel A. Causes of sexual dimorphism in performance traits: a comparative approach. Evolutionary Ecology Research 2008; 10: 229-250.
27. Berns CM. The Evolution of Sexual Dimorphism: Understanding Mechanisms of Sexual Shape Differences. London, UK: IntechOpen Limited; 2013. doi: 10.5772/55154
28. Barone R. Comparative Anatomy of Domestic Mammals. Volume 2: Artrology and Myology. Paris, France: Vigot; 2000 (In French).