LILJE, K.E.; FISCHER, M.S.: Limb proportions in forelimbs of Bovidae and Cervidae

Previous studies of limb bone scaling consider the relationship between forearm bones (humerus, radius, metacarpus) and body mass, or the relationships of forearm bones to each other. Studies of locomotion in small and medium-sized mammals clearly demonstrate that scapular retraction is the most important source of propulsion in the forelimb (Fischer et al., J. Exp. Biol. in press). Taking these data into account, the proximal element of the forelimb-chain has to be included into scaling relationships concerning the anterior extremity. The anatomical length of forelimb bones including the scapula were measured in nearly 50 species of Bovidae and 20 species of Cervidae. A regression model (reduced major axis) was used for analysing the whole data sample and for the sample divided according to phylogenetic relationships (Bovidae and Cervidae). In bovid forelimbs, the scapula is the element which lengthens the most with increasing body mass, more than humerus, radius and metacarpus (in this sequence). In contrast, the distal segment is elongates more with increasing body mass in Cervidae, followed by radius, scapula and humerus.