The superficial layer of the Musculus masseter and the well-developed process of the maxilla in the tiger Panthera tigris.

Abstract

The musculature and functional anatomy of the head and skull of a tiger Panthera tigris were, examined and compared with those of various other felid species. The Musculus masseter is divided into three layers. The superficial layer of which is well-developed and further sub-divided into lateral and medial components. The ventro-caudal fleshy portion of the lateral component originates behind the last upper molar, where it is attached by a strong tendon to the tubercle tuber maxillae. The medial component, which runs dorso-ventrally, has a particularly well-developed fleshy portion. The present anatomical study suggests that in the tiger, large masseteric forces are produced in both ventro-rostral and ventro-dorsal directions. In the tiger, a process is present on the tubercle of the maxilla from which the strong tendon originates. This process is also apparent in the leopard Panthera pardus, the jaguar P. onca and the puma Felis concolor. It is not found, however, in either the domestic cat F. catus or the Iriomote wild cat F. iriomotensis. Comparisons between the skulls of various species of felidae indicate that whereas the puma, the leopard and the jaguar each possess the strong tendon, which bundles the ventro-caudal fleshy portion of the lateral component, the domestic cat and the Iriomote wild cat only possess weak tendons attaching to this component.