Document Type : Original Article
Authors
1
Department of Anatomy & Embryology. Fac. Vet. Med., University of Sadat City, EGYPT & Discipline of Anatomy and Pathology, School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Australia.
2
Department of Cytology and Histology, Faculty of Veterinary Medicine, University of Sadat City, Sadat City, Egypt.
Abstract
The cassowaries are ratites (flightless birds without a keel on their sternum). The wings and feet of a doubled-wattled or Southern cassowary used in this study were radiographed. Pieces of the quills and claws were processed for histological examination, and the wings and feet were cleaned to study the bones.
The wings are small with only four long, slightly curved quills or remeges. Quills occurred in follicles, similar to the hair follicles of mammals. The shaft of a quill was for med by a central medulla consisting of a solid polygonal, non-nucleated cell mass surrounded by dense compact keratinized cells compressed to form a cortex.
The wing skeleton was formed by the humerus, a thick radius paired with a thinner curved ulna, ulnar and radial carpals, carpometacapal, and three digits. The second digit bore a long curved claw.
The skeleton of the foot was formed by the distal extremity of the tarsometatarsal, which had three articular surfaces (trochlea) representing the three digits (II, III, IV).
The first digit was missing. The second digit consisted of 3 phalanges, the distal phalanx of which was a long tapering cone sheathed completely by a keratinous long straight claw (dagger-shaped). The third digit was the largest, and consisted of 4 phalanges. The fourth digit was longer than the second one and shorter than the third one, and had five phalanges.
The gross anatomy described was supported by 8 images (x-rays, histology, and skeleton of the wings and feet) and discussed in comparison with other bird species.
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