Osteometry of the skull of one-humped camels. Part I: immature animals.

The aim of this study was to investigate osteometric indices of immature camels (2-3 years old) in Nigeria. The cranial length, viscerocranial length, maximum zygomatic width, neurocranial volume, skull and facial index for females and males were 22.1 cm and 22.3 cm; 16.3 cm and 16.7 cm; 15.8 cm and 16.1 cm; 479 ml and 496 ml; 40.9 and 41.3, and 96.4 and 96.2 respectively. The mean orbital horizontal and vertical diameters of young camels were similar to each other giving a near complete circular shape. The foramen magnum index was over 100 because of a relatively higher height than width. The data were compared with those of other types of immature camels in the literature and will be useful for anatomical, developmental, anthropological and clinical studies of camels.

Investigation of the osteometry of the skull of the one-humped camels. Part II: sex dimorphism and geographical variations in adults.

Sexual dimorphism in the skull of different species has been of importance in archaeological, forensic and anatomical studies; also, a variation in phenotypic and genetic traits across geographic space is a recurring phenomenon in biological species. This study investigated 10 adult camels from each of three geographical locations in northern Nigeria, for sex- and location-based variations in the skulls. In one location, male skulls had greater absolute osteometric values but there were no significance differences in relative proportions between sexes. Moreover, all index values (skull, cranial and facial) indicate no sexual dimorphism in all locations. There were some variations in the osteometry of the frontal region, and neurocranial volume between the locations. In addition it was observed that the skull index of Nigerian camels was similar to the Malha type documented in literature but wide variations exist in many other craniometric dimensions of the skull. This suggests a definite difference in phenotype and probable origin.