Cranial study of the Caspian freshwater turtle, Mauremys caspica (Gmelin, 1774) (Testudines: Geoemydidae) in Western Iran

The skull morphology and origin of turtles is one of the long-lasting debates in evolutionary researchs. Skull change to anapsid, transformed that to an akinetic and unique structure capable of reorienting the jaw contracting muscle. These changes are thought to be strongly related to functional adaptations, especially biting performance. The present study provides detailed description of the osteocranial structure of the Caspian terrapin, Mauremys caspica, in western Iran. Examined specimens were collected from Dinavar river in Kermanshah Province. Using common protocols for bone cleansing, the skulls were removed and scanned, and photographed using a loop equipped with digital camera. The skull of Testudo graeca encompass 39 bones (18 pairs and three single bones) that is including a flat skull roof, numerous extremely wide skull elements, and a compressed neurocranium possibly the functional result of life habit, Our results showed that specific variations in skull osteology, including scale, shape, location and articulation, can have different effects on animal behavior.