Macro-anatomical examination of ossa cranii in blackbird (turdus merula)

Aim: Macro-anatomical importance of ossa cranii is increasing since the bones that make up the head skeleton in birds have the greatest diversity in the vertebrate group. Within this scope, macro-anatomical examination of ossa cranii in blackbird will contribute to the elimination of the lack of information in this area. Material and Method: In this research, regardless of gender, skulls of six male and six female adult blackbirds were examined macro-anatomically by maceration. Images of materials examined were taken from different angles under a 50 mm classical magnifying glass. Results: It is determined that blackbirds have no suturas between their skull bones and have aegithognath type skull structure. It was observed that neurocranium was composed of occipital, sphenoid, parietal, frontal and temporal bone; also, ethmoid bone was included in the splanchnocranium part by the pressure of orbita. It was found that the triangular sphenoid bone forms a large part of the ventral part of the cavum cranii. It was determined that the temporal bone plays an important role in the formation of the lateral wall of the cavum cranii. Additionally, splanchnocranium bones are constituted of lacrimal, nasal, incisive, maxilla, zygomatic, palatine, pterygoid, vomer, quadratum, mandible and hyoid bones. Lacrimal bone was found to be oval and blunt ended. It was seen that nasal bone determines dorsal and lateral borders of the cavum nasi and also nostrils are formed at the end of fusion of extensions constituted together with intermaxillare and nasal bone. It was determined that proc. palatinus of maxilla bone contribute to the shape of palate. Zygomatic bone was also a thin, long, rod-shaped bone formed by the fusion of os jugale and os quadratatojugale, while os vomer was present as a nucleus in this region. It was seen that the mandibula shapes the skeleton of the lower jaw and this bone was formed by incorporating os angulare, os articulare, os supraangulare, os complamentare, os oparculare and os dentale bones. It was observed that the basihyoideum forming the body of the os hyoid bone was rod shaped, and the os entoglossum attached to it was in the shape of a shovel. Conclusion: It was concluded that data obtained in this study would contribute to the lack of information in this area and it might be a source for systematic field researchersto use in taxonomy. Key Words: Blackbird, neurocranium, ossa cranii, skull, turdus merula.