Document Type : Original Article

Authors

1 Department of Basic science, faculty of veterinary medicine, University of Tehran, Tehran, Iran.

2 Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

3 Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

4 Department of Anatomy, Fauclty of Veterinary Medicine, Ankara University, Ankara, Turkey.

5 DVM Student, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

6 Veterinary Radiologist, DVM, DVSc, from Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

7 DVM Graduated Student, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

Abstract

Limited information about the skeletal anatomical features of the European pond turtle (Emys orbicularis), one of the species of turtles in Iran, is available. Given that performing clinical examinations as well using imaging techniques require complete anatomical information of the animal, it is essential to study these features in various researches. This study was done to provide complete anatomical information of the vertebrae and different shell parts in European pond turtles, as well as their normal three-dimensional computed tomographic (3D CT)-Scan images in both flexed and extended neck positions. This study was performed on 10 European pond turtles. CT-Scan images were taken from each sample and in the 3D reconstruction of the images, different patterns were used. 8 cervical vertebrae, 10 dorsal vertebrae, 2 sacral vertebrae, and 25 caudal vertebrae were observed in European pond turtles. The cervical vertebrae were highly mobile and there were no cervical ribs. Due to the fusion of the dorsal vertebrae, there were no intervertebral foramina in this section, but very small lateral vertebral foramina were visible. These foramina were formed in the last four dorsal vertebrae at the fusion site and they were larger than the foramina of the cranial vertebrae. According to the results of this study, it can be concluded that the use of diagnostic techniques such as a 3D CT-Scan is very useful in the study of skeletons. The correct direction and position of the bones can be easily determined using this technique. Part of the turtle`s ability to contract the neck is due to the special structure of the articular processes of the last two cervical vertebrae and the first dorsal vertebra. One of the most important adaptations in the evolution of the special structure of the seventh and eighth vertebrae of the neck and the way they are articulated.

Keywords

Main Subjects

  1. Getty R, Sisson S. Sisson and Grossman's the Anatomy of the Domestic Animals. 5th ed. WB Saunders, Philadelphia, US, 1975.
  2. Valente AL, Cuenca R, Parga ML, Lavín S, Franch J, Marco I. Cervical and coelomic radiologic features of the loggerhead sea turtle, Caretta caretta. Canadian Journal of Veterinary Research. 2006; 70(4): 285.
  3. Valente AL, Marco I, Zamora MA, Parga ML, Lavín S, Alegre F, Cuenca R. Radiographic features of the limbs of juvenile and subadult loggerhead sea turtles (Caretta caretta). Canadian Journal of Veterinary Research. 2007; 71(4): 305.
  4. Wyneken J. The external morphology, musculoskeletal system, and neuro-anatomy of sea turtles. The Biology of Sea Turtles. 2003; 2: 39-77.
  5. Lyson TR, Joyce WG. Evolution of the turtle bauplan: the topological relationship of the scapula relative to the ribcage. Biology Letters. 2012; 8(6): 1028-1031.
  6. Sheil CA. Osteology and skeletal development of Apalone spinifera (Reptilia: Testudines: Trionychidae). Journal of Morphology. 2003; 256(1): 42-78.
  7. Sánchez-Villagra MR, Müller H, Sheil CA, Scheyer TM, Nagashima H, Kuratani S. Skeletal development in the Chinese soft-shelled turtle Pelodiscus sinensis (Testudines: Trionychidae). Journal of Morpholgy. 2009; 270(11): 1381-1399.
  8. Sheil CA, Greenbaum E. Reconsideration of skeletal development of Chelydra serpentina (Reptilia: Testudinata: Chelydridae): evidence for intraspecific variation. Journal of Zoology. 2005; 265(3): 235-267.
  9. Fabrezi M, Manzano A, Abdala V, Zaher H. Developmental basis of limb homology in Pleurodiran turtles, and the identity of the hooked element in the chelonian tarsus. Zoological Journal of the Linnean Society. 2009; 155(4): 845-866.
  10. Delfino M, Fritz U, Sánchez-Villagra MR. Evolutionary and developmental aspects of phalangeal formula variation in pig-nose and soft-shelled turtles (Carettochelyidae and Trionychidae). Organisms Diversity & Evolution. 2010; 10(1): 69-79.
  11. Werneburg I, Hugi J, Müller J, Sánchez‐Villagra MR. Embryogenesis and ossification of Emydura subglobosa (Testudines, Pleurodira, Chelidae) and patterns of turtle development. Developmental Dynamics: an official publication of the American Association of Anatomists. 2009; 238(11): 2770-2786.
  12. Sheil CA. Skeletal development of Macrochelys temminckii (Reptilia: Testudines: Chelydridae). Journal of Morphology. 2005; 263(1): 71-106.
  13. Nagashima H, Sugahara F, Takechi M, Ericsson R, Kawashima-Ohya Y, Narita Y, Kuratani S. Evolution of the turtle body plan by the folding and creation of new muscle connections. Science. 2009; 325(5937): 193-196.
  14. Tulenko FJ, Sheil CA. Formation of the chondrocranium of Trachemys scripta (Reptilia: Testudines: Emydidae) and a comparison with other described turtle taxa. Journal of Morphology. 2007; 268(2): 127-151.
  15. Bona P, Alcalde L. Chondrocranium and skeletal development of Phrynops hilarii (Pleurodira: Chelidae). Acta Zoologica. 2009; 90(4): 301-325.
  16. Bever GS. The postnatal skull of the extant North American turtle Pseudemys texana (Cryptodira: Emydidae), with comments on the study of discrete intraspecific variation. Journal of Morphology. 2009; 270(1): 97-128.
  17. Jamniczky H, Russell A. Cranial arterial foramen diameter in turtles: a quantitative assessment of size-independent phylogenetic signal. Animal Biology. 2004; 54(4): 417-436.
  18. TaŞkavak E. Comparative morphology of the Euphrates soft-shelled turtle, Rafetus euphraticus (Daudin, 1802) (Reptilia, Testudines) in Southeastern Anatolia. Amphibia-Reptilia. 1998; 19(3): 281-291.
  19. Zehtabvar O. Tootian Z, Vajhi A, shojaei B, Rostami A, Davudypoor S, Sadeghinezhad J, Ghaffari H, Memarian I. Computed tomographic anatomy and topography of the lower respiratory system of the European pond turtle (Emys orbicularis). Iranian Journal of Veterinary Surgery. 2014; 9(2):9-16.
  20. Anderson SC. Synopsis of the turtles, crocodiles, and amphisbaenians of Iran. California Academy of Sciences.1979; 20(14): 501-528.