Functional Significance of Anatomical Accommodation in the Skull of Common Hoopoe, Upupa Epops (Bucerotiformes, Upupidae)

Abstract

The present study aims to supplement anatomical data about the cranial skeleton and describe some cranial modifications of the common hoopoe, Upupa epops Linnaeus, 1758, by using several techniques. The common hoopoe has small skull and characterized by presence of air space (pneumatization) within their bones. The degree of pneumatization increased especially within the temporal region. The skull of the common hoopoe possesses different types of kinetic hinges; one hinge locates between frontal and nasal region (frontonasal hinge) allows depression/elevation of upper beak relative to brain case. The other one exhibits between the upper beak and jugal bar (maxilla-jugal hinge). The skull of the common hoopoe characterizes by presence of powerful jaw ligamentous system. One of these ligaments exhibits ossification (Lig. Jugomandibularis medialis). In addition, a long mandibular symphysis observes between the two rami of the anterior third of the lower beak. This mandibular symphysis seems longer in the dorsal surface than the ventral one form ventral gap between the two rami of mandible. These modifications of the cranial skeleton of common hoopoe and jaw ligaments consider features of adaptation for probe mechanism, as well as exhibit its phylogenetic relationship with other avian species.