Gross anatomy of the oropharyngeal cavity in the ostrich (Struthio camelus)

There are significant structural differences between the mouth and pharyngeal cavity of birds and mammals. It is usual to refer to a common oropharyngeal cavity of birds because the soft palate, which forms such an obvious delineation between the mouth and pharyngeal cavity, is absent. Six male adult ostriches were used to study the oropharyngeal cavity and its components including the beak, hard palate, pharynx, tongue and the larynx macroscopically. This study revealed that these components in ostrich have different features from other birds. In the ostrich, the beaks are spoon-shaped and the tongue is characterized by a short, broad and semicircular form. The hard palate is concave with a prominent median mucosal fold in its 2/3 rostral area and two oblique choanal slits in its caudal third area. The roof of pharynx presents infundibular slit in midline, a deep concave notch in caudal border and pharyngeal tonsils on its dorsal surface. The larynx protrudes from the floor of pharynx and consists of the unpaired cricoid cartilage and the paired arytenoid cartilages.