Morphometric and Normal 2D CT Anatomic Study of the Vertebral Column of the European Pond Turtle (Emys orbicularis)

Background: European pond turtle is one of the two species of freshwater turtles in Iran. Regarding clinical examinations and diagnostic imaging techniques, it is necessary to have complete anatomical information on this turtle. Objectives: This study provided complete morphometric and normal two-dimensional computerized tomographic scanning information of the vertebrae of European pond turtles. Methods: Ten European pond turtles were used in this study. Computerized tomography (CT) scans were taken from each anesthetized turtle. Then, morphometric parameters were measured in the CT scans of the vertebral column. Results: Atlas was the shortest of the cervical vertebrae, and the eighth cervical vertebra was shorter than the previous vertebrae. The articular surface of the caudal articular processes of the eighth cervical vertebra was bent, and these surfaces were almost vertical. Transverse process width had remained constant in the cervical vertebrae. The transverse process was not observed in the dorsal vertebrae. The first dorsal vertebra had a different shape than others. Conclusion: The particular shape of the last two cervical vertebrae, especially the arched shape of the eight vertebrae. The seventh and eighth cervical vertebrae have the largest transverse distance between caudal articular processes that seem necessary for cervical motion. The limited space of the caudal cervical vertebrae inside the shell chamber can be the reason for the reduction in the length of these vertebrae. The absence of a spinous process in the seventh and eighth cervical vertebrae of the neck may be related to their specific position in the neck retraction.