Axial skeletal morphological studies on the helmeted Guinea fowl (Numida meleagridis).

Abstract

This study on the morphological features of bones of the helmeted guinea fowl (Numidia meleagridis) specifically the axial skeleton was conducted for documentation and valuable information on differences when compared with other species of the same order. Ten (10) Helmeted guinea fowls (5 females and 5 males) with an average weight of 3.0 kg were euthanized via jugular vein severance with bone preparation achieved via the use of insect larvae. The skull presented an elongated structure made up of paired and unpaired flat, short and long bones with distinctive features. The frontal bone projected caudodorsally to form a horn like structure, the frontal process at its middle while the vomer was absent. The cervical vertebrae were 14 in number starting from the first (Atlas) to the last vertebra without a rib. Specific distinguishing features were evident in the Atlas, Axis, 3rd to 5th, 6th to 11th and 12th to 14th cervical vertebrae. The thoracic vertebrae presented 7 bones comprising the 1st single free vertebra; notarium (fused 2nd to 5th), 6th single free vertebra and the last 7th vertebrae that fused with the synsacrum which was an ankylosis of the lumbar and sacral vertebrae. The caudal vertebrae were 7 with the last; the pygostyle being distinct in appearance. The ribs were 7 pairs, of which the first two were asternal while the remaining five were sternal and consisted of proximal vertebral and distal sternal portions. The curved uncinate process articulated to the caudal border of the 2nd and vertebral portions of the 3rd to 5th ribs. The guinea fowl proved to be a carinate by presenting a single sternum with dorsolateral processes and a ventral carina. In conclusion, this study revealed that except for the skull, the axial skeleton of the Helmeted Guinea fowl presented similarities to that of the domestic fowl (Gallus domesticus).