A comparative study on the morphology, radiography and computed tomography of the skull bones of barking deer (Muntiacus muntjak) and sambar deer (Rusa unicolor).

Abstract

There is scanty information on the skull morphology of barking and sambar deer; thus the present study was designed to provide information on morphology, radiography and computed tomography (CT) of the skull bones of both deer species. The study was conducted on 12 skulls of adult barking deer (n = 6) and sambar deer (n = 6) of either sex (n = 3 males and n = 3 females) collected from Aizawl Zoological Park, Aizawl, Mizoram. The skulls of both species were macerated as per the standard maceration techniques. The skull bones of both deer species were divided into a neurocranium and a viscerocranium. The neurocranium was comprised of occipital, sphenoid, temporal, frontal, parietal, interparietal and ethmoid bones. The viscerocranium consisted of nasal, lacrimal, zygomatic, maxilla, incisive, palatine, pterygoid, vomer, mandible, turbinates and hyoid bones. The cranial cavity was oval and elongated caudally. The orbit was round, complete in barking deer; however, it was oval, complete in sambar deer. The facial tuberosity was present caudal to infraorbital foramen and dorsally at superior third premolar tooth in barking deer whereas dorsally at the superior first molar tooth in sambar deer. The infraorbital foramina were small, elliptical and placed at the level of the superior first premolar tooth. The alveolus for a canine tooth was present rostrally in the maxilla of both species. Turbinates bones were visible and mandibular symphysis remained unossified on radiographs and CT in both species. The radiographs of both species showed that the nasal canal was divided by the nasal septum. The CT scan demonstrated the paranasal, frontal and maxillary sinuses. The present study is important in the comparative anatomy of ruminant species and may help the wildlife forensic officials to identify and differentiate the bones of these two species from those of other domestic and wild small ruminants.