Abstract:
The mammalian forelimb is adapted to different functions including postural, locomotor, feeding, exploratory,
grooming and defense. Comparative studies on morphology of the mammalian scapula have been performed in an
attempt to establish the functional differences in the use of the forelimb. In this study, a total of 102 scapulae
collected from 66 species of animals, representatives of all major taxa from rodents, sirenians, marsupials, pilosa,
cetaceans, carnivores, ungulates, primates and apes were analyzed. Parameters measured included scapular length,
width, position, thickness, area, angles and index. Structures included supraspinous and infraspinous fossae, scapular
spine, glenoid cavity, acromium and coracoid processes. Images were taken using computed tomographic (CT)
scanning technology (CT-Aquarium, Toshiba and micro CT- LaTheta, Hotachi, Japan) and measurement values
acquired and processed using Avizo computer software and CanvasTM 11 ACD systems. Statistical analysis was
performed using Microsoft Excel 2013. Results obtained showed that there were similar morphological
characteristics of scapula in mammals with arboreal locomotion and living in forest and mountainous areas but
differed from those with leaping and terrestrial locomotion living in open habitat or savannah. The cause for the
statistical grouping of the animals signifies presence of the close relationship between habitat and scapular
morphology and in a way that corresponds to type of locomotion and speed. The morphological characteristics of
the scapula and functional interpretation of the parameters in relation to habitat of each taxon is discussed in detail.
