Three-dimensional morphological variation and sexual dimorphism in the humerus of dromedary camels (Camelus dromedarius) from El Oued region: a geometric morphometric analysis
Abstract
This study investigates the three-dimensional morphological variation and allometric relationships in the humerus of dromedary camels (Camelus dromedarius) from the El Oued region, with a focus on sex-based differences. The aim is to analyze the morphological diversity and sexual dimorphism in the humeri of dromedary camels using advanced geometric morphometric techniques. This includes discerning patterns of variation and covariation, particularly related to sexual dimorphism and size-related shape changes. A sample of 59 humeri (29 males and 30 females) was collected. High-resolution three-dimensional scans were used to capture detailed shapes, followed by Procrustes superimposition and Principal Component Analysis to analyze the data. The analysis revealed significant sexual dimorphism, with male camels having more robust and thicker humeri compared to the more slender and delicate humeri of female camels. The allometric analysis showed notable size-related shape changes, especially in the deltoid tuberosity and distal epiphysis regions. The study underscores the presence of sexual dimorphism and its impact on the functional morphology of camelid skeletal structures. The findings provide valuable comprehension into the adaptation pressures and functional demands shaping these bones, demonstrating the utility of geometric morphometrics as a powerful tool in skeletal morphology studies. This research sets a new standard for future studies by integrating high-resolution three-dimensional scanning with sophisticated morphometric analyses.
Ethical Statement
This study was conducted in accordance with the ethical standards for animal research. All procedures involving the handling and sampling of dromedary camels (Camelus dromedarius) were approved by the Committee of Ethics of the University of Souk Ahras in Algeria (Approval no: 2021/08704-180).
Supporting Institution
This research did not receive any financial support or funding from external sources.
Thanks
We extend our deepest gratitude to the Agricultural Services Directorate of the Wilaya of El Oued for their invaluable support and cooperation throughout this study. Their assistance in facilitating fieldwork and providing access to essential resources was crucial to the success of our research.
References
- 1. Adah AS, Ayo JO, Adah DA (2023): Unique physiological and behavioural adaptive features of the One-Humped Camel (Camelus dromedarius) to arid environments. J Appl Vet Sci, 8, 57-64.
- 2. Ajanović Z, Ajanović U, Dervišević E, et al (2023): Three-dimensional models of human skulls and their application in sex differences analysis of midsagittal line. Veterinaria, 72, 261-270.
- 3. Alhajeri BH, Alhaddad H, Alaqeely R, et al (2021): Camel breed morphometrics: current methods and possibilities. Trans R Soc S Aust, 145, 90-111.
- 4. Batur B, Kiliçli İB, Yunus HA, Şahi̇n S, et al (2025): Geometric morphometric analysis of plastinated brain sections using computer-based methods: Evaluating shrinkage and shape changes. Anat. Anz, 257, 152351.
- 5. Boz İ, Altundağ Y, Szara T, et al (2023): Geometric morphometry in veterinary anatomy. Veterinaria, 72, 15-27. 6. Çakar B, Tandir F, Güzel BC, et al (2024): Comparison of skull morphometric characteristics of simmental and holstein cattle breeds. Animals, 14, 2085.
- 7. Demiraslan Y, Demircioğlu İ, Güzel BC (2024): Geometric analysis of mandible using semilandmark in Hamdani and Awassi sheep. Ankara Univ Vet Fak Derg, 71, 19-25.
- 8. Fesseha H, Desta W (2020): Dromedary camel and its adaptation mechanisms to desert environment: a review. Int J Zoology Stu, 5, 23-8.
- 9. Giray CN, Çakar B, Manuta N, et al (2024): Three-dimensional morphological variation and allometric analysis in dog scapula. Veterinaria, 73, 25-33.
- 10. Gould SJ (1966): Allometry and size in ontogeny and phylogeny. Biol Rev, 41, 587-640.
- 11. Gupta SK, Deshmukh SK, Karmore SK (2015): Grossmorphometrical study on the forearm bones of camel (Camelus dromedarius). Vet Pract, 16, 286-287.
- 12. Gündemir O, Michaud M, Altundağ Y, et al (2024): Chewing asymmetry in dogs: Exploring the importance of the fossa masseterica and first molar teeth morphology. Anat Histol Embryol, 53, e13050.
- 13. Gündemir O, Szara T (2025): Morphological patterns of the European bison (Bison bonasus) skull. Sci Rep, 15, 1418.
- 14. Iglesias Pastran C, Navas González FJ, Ciani E, et al (2024): Determination of breeding criteria for gait proficiency in leisure riding and racing dromedary camels: a stepwise multivariate analysis of factors predicting overall biomechanical performance. Front Vet Sci, 10, 1297430.
- 15. Jashari T, Kahvecioğlu O, Duro S (2023): Morphometric analysis for the sex determination of the skull of the DeltariIlir dog (Canis lupus familiaris) of Kosovo. Anat Histol Embryol, 51, 443-451.
- 16. Kendall DG (1984): Shape manifolds, Procrustean metrics, and complex projective spaces. Bull Lond Math Soc, 16, 81-121.
- 17. Korkmazcan A, Ünal B, Bakici C, et al (2025): Exploring skull shape variation and allometry across different chicken breeds. Ankara Univ Vet Fak Derg, 72, 1-7.
- 18. Lawing AM, Polly PD (2010): Geometric morphometrics: recent applications to the study of evolution and development. J Zool, 280, 1-7.
- 19. Macleod N (2002): Geometric morphometrics and geological shape-classification systems. Earth Sci Rev, 59, 27-47.
- 20. Manuta N, Çakar B, Gündemir O, et al (2024). Shape and size variations of distal phalanges in cattle. Animals, 14, 194.
- 21. Marcus LF, Corti M, Loy A, et al (1996): Advances in Morphometrics. NATO ASI Ser A Life Sci. Plenum Press, 14-35.
- 22. O'Higgins P (2000): The study of morphological variation in the hominid fossil record: biology, landmarks and geometry. J Anat, 197, 103-120.
- 23. Perez SI, Bernal V, Gonzalez PN (2006): Differences between sliding semi-landmark methods in geometric morphometrics, with an application to human craniofacial and dental variation. J Anat, 208, 769-784.
- 24. Porto A, Rolfe S, Maga AM (2021): ALPACA: A fast and accurate computer vision approach for automated landmarking of three-dimensional biological structures. Methods Ecol Evol, 12, 2129-2144.
- 25. Rahim SA (1997): Studies on the age of puberty of male camels (Camelus dromedarius) in Saudi Arabia. Vet J, 154, 79-83.
- 26. Ralls K (1976): Mammals in which females are larger than males. Q Rev Biol, 51, 245-276.
- 27. Richtsmeier JT, Deleon VB, Lele SR (2002): The promise of geometric morphometrics. Yearb Phys Anthropol, 45, 63-94.
- 28. Richtsmeier JT, Lele SR, Cole TM (2005): Landmark morphometrics and the analysis of variation. In: Hallgrímsson B, Hall BK (Eds.), Variation: A Central Concept in Biology. Elsevier Academic Press, 153-162.
- 29. Rohlf FJ (1990): Morphometrics. Annu Rev Ecol Syst, 21, 299-316.
- 30. Rohlf FJ (1998): On applications of geometric morphometrics to studies of ontogeny and phylogeny. Syst Biol, 47, 147-158.
- 31. Rohlf FJ (1999): Shape statistics: Procrustes superimpositions and tangent spaces. J Classif, 16, 197-223.
- 32. Rohlf FJ (2003): Bias and error in estimates of mean shape in geometric morphometrics. J Hum Evol, 44, 665-683.
- 33. Webster MA, Sheets HD (2010): A practical introduction to landmark-based geometric morphometrics. Paleonto Soc Pap, 16, 163-188.
- 34. Zelditch ML, Swiderski DL, Sheets HD, et al (2012): Geometric Morphometrics for Biologists: A Primer. Elsevier, 43-61.
Three-Dimensional Morphological Variation and Sexual Dimorphism in the Humerus of Dromedary Camels (Camelus dromedarius) from El Oued Region: A Geometric Morphometric Analysis
Abstract
This study investigates the three-dimensional morphological variation and allometric relationships in the humerus of dromedary camels (Camelus dromedarius) from the El Oued region, with a focus on sex-based differences. The aim is to analyze the morphological diversity and sexual dimorphism in the humeri of dromedary camels using advanced geometric morphometric techniques. This includes discerning patterns of variation and covariation, particularly related to sexual dimorphism and size-related shape changes. A sample of 59 humeri (29 males and 30 females) was collected. High-resolution 3D scans were used to capture detailed shapes, followed by Procrustes superimposition and Principal Component Analysis (PCA) to analyze the data. The analysis revealed significant sexual dimorphism, with male camels having more robust and thicker humeri compared to the more slender and delicate humeri of female camels. The allometric analysis showed notable size-related shape changes, especially in the deltoid tuberosity and distal epiphysis regions. The study underscores the presence of sexual dimorphism and its impact on the functional morphology of camelid skeletal structures. The findings provide valuable insights into the adaptation pressures and functional demands shaping these bones, demonstrating the utility of geometric morphometrics as a powerful tool in skeletal morphology studies. This research sets a new standard for future studies by integrating high-resolution 3D scanning with sophisticated morphometric analyses.
References
- 1. Adah AS, Ayo JO, Adah DA (2023): Unique physiological and behavioural adaptive features of the One-Humped Camel (Camelus dromedarius) to arid environments. J Appl Vet Sci, 8, 57-64.
- 2. Ajanović Z, Ajanović U, Dervišević E, et al (2023): Three-dimensional models of human skulls and their application in sex differences analysis of midsagittal line. Veterinaria, 72, 261-270.
- 3. Alhajeri BH, Alhaddad H, Alaqeely R, et al (2021): Camel breed morphometrics: current methods and possibilities. Trans R Soc S Aust, 145, 90-111.
- 4. Batur B, Kiliçli İB, Yunus HA, Şahi̇n S, et al (2025): Geometric morphometric analysis of plastinated brain sections using computer-based methods: Evaluating shrinkage and shape changes. Anat. Anz, 257, 152351.
- 5. Boz İ, Altundağ Y, Szara T, et al (2023): Geometric morphometry in veterinary anatomy. Veterinaria, 72, 15-27. 6. Çakar B, Tandir F, Güzel BC, et al (2024): Comparison of skull morphometric characteristics of simmental and holstein cattle breeds. Animals, 14, 2085.
- 7. Demiraslan Y, Demircioğlu İ, Güzel BC (2024): Geometric analysis of mandible using semilandmark in Hamdani and Awassi sheep. Ankara Univ Vet Fak Derg, 71, 19-25.
- 8. Fesseha H, Desta W (2020): Dromedary camel and its adaptation mechanisms to desert environment: a review. Int J Zoology Stu, 5, 23-8.
- 9. Giray CN, Çakar B, Manuta N, et al (2024): Three-dimensional morphological variation and allometric analysis in dog scapula. Veterinaria, 73, 25-33.
- 10. Gould SJ (1966): Allometry and size in ontogeny and phylogeny. Biol Rev, 41, 587-640.
- 11. Gupta SK, Deshmukh SK, Karmore SK (2015): Grossmorphometrical study on the forearm bones of camel (Camelus dromedarius). Vet Pract, 16, 286-287.
- 12. Gündemir O, Michaud M, Altundağ Y, et al (2024): Chewing asymmetry in dogs: Exploring the importance of the fossa masseterica and first molar teeth morphology. Anat Histol Embryol, 53, e13050.
- 13. Gündemir O, Szara T (2025): Morphological patterns of the European bison (Bison bonasus) skull. Sci Rep, 15, 1418.
- 14. Iglesias Pastran C, Navas González FJ, Ciani E, et al (2024): Determination of breeding criteria for gait proficiency in leisure riding and racing dromedary camels: a stepwise multivariate analysis of factors predicting overall biomechanical performance. Front Vet Sci, 10, 1297430.
- 15. Jashari T, Kahvecioğlu O, Duro S (2023): Morphometric analysis for the sex determination of the skull of the DeltariIlir dog (Canis lupus familiaris) of Kosovo. Anat Histol Embryol, 51, 443-451.
- 16. Kendall DG (1984): Shape manifolds, Procrustean metrics, and complex projective spaces. Bull Lond Math Soc, 16, 81-121.
- 17. Korkmazcan A, Ünal B, Bakici C, et al (2025): Exploring skull shape variation and allometry across different chicken breeds. Ankara Univ Vet Fak Derg, 72, 1-7.
- 18. Lawing AM, Polly PD (2010): Geometric morphometrics: recent applications to the study of evolution and development. J Zool, 280, 1-7.
- 19. Macleod N (2002): Geometric morphometrics and geological shape-classification systems. Earth Sci Rev, 59, 27-47.
- 20. Manuta N, Çakar B, Gündemir O, et al (2024). Shape and size variations of distal phalanges in cattle. Animals, 14, 194.
- 21. Marcus LF, Corti M, Loy A, et al (1996): Advances in Morphometrics. NATO ASI Ser A Life Sci. Plenum Press, 14-35.
- 22. O'Higgins P (2000): The study of morphological variation in the hominid fossil record: biology, landmarks and geometry. J Anat, 197, 103-120.
- 23. Perez SI, Bernal V, Gonzalez PN (2006): Differences between sliding semi-landmark methods in geometric morphometrics, with an application to human craniofacial and dental variation. J Anat, 208, 769-784.
- 24. Porto A, Rolfe S, Maga AM (2021): ALPACA: A fast and accurate computer vision approach for automated landmarking of three-dimensional biological structures. Methods Ecol Evol, 12, 2129-2144.
- 25. Rahim SA (1997): Studies on the age of puberty of male camels (Camelus dromedarius) in Saudi Arabia. Vet J, 154, 79-83.
- 26. Ralls K (1976): Mammals in which females are larger than males. Q Rev Biol, 51, 245-276.
- 27. Richtsmeier JT, Deleon VB, Lele SR (2002): The promise of geometric morphometrics. Yearb Phys Anthropol, 45, 63-94.
- 28. Richtsmeier JT, Lele SR, Cole TM (2005): Landmark morphometrics and the analysis of variation. In: Hallgrímsson B, Hall BK (Eds.), Variation: A Central Concept in Biology. Elsevier Academic Press, 153-162.
- 29. Rohlf FJ (1990): Morphometrics. Annu Rev Ecol Syst, 21, 299-316.
- 30. Rohlf FJ (1998): On applications of geometric morphometrics to studies of ontogeny and phylogeny. Syst Biol, 47, 147-158.
- 31. Rohlf FJ (1999): Shape statistics: Procrustes superimpositions and tangent spaces. J Classif, 16, 197-223.
- 32. Rohlf FJ (2003): Bias and error in estimates of mean shape in geometric morphometrics. J Hum Evol, 44, 665-683.
- 33. Webster MA, Sheets HD (2010): A practical introduction to landmark-based geometric morphometrics. Paleonto Soc Pap, 16, 163-188.
- 34. Zelditch ML, Swiderski DL, Sheets HD, et al (2012): Geometric Morphometrics for Biologists: A Primer. Elsevier, 43-61.
Details
| Primary Language | English |
|---|---|
| Subjects | Veterinary Anatomy and Physiology |
| Journal Section | Research Article |
| Authors | |
| Early Pub Date | March 4, 2025 |
| Publication Date | |
| Submission Date | December 30, 2024 |
| Acceptance Date | February 10, 2025 |
| Published in Issue | Year 2025Accepted Papers |