抄録
The muscles of the forelimb were functional-morphologically examined in a carcass of the aardvark (Orycteropus afer) that is highly adapted to the fossorial life and the digging behavior. The M. pronator quadratus, the M. abductor digiti I longus, the M. brachioradialis, the M. pronator teres and the M. supinator are well-developed. We suggest that the supinator-pronator movement by these muscles enables the aardvark to dig, crush and sweep the soils in its fossorial behavior. In addition, the M. extensor digiti II runs obliquely to rotate the forearm around the ulna shaft. We think that this muscle may not only function as an extensor of the digits II and III, but also as a supinator of the fore arm. Many extensor muscles can be separated into two groups on the basis of their insertion. The M. extensor digiti II and the M. extensor carpi radialis insert to the digits-metacarpals II-III, whereas the M. extensor digitorum lateralis and M. extensor carpi ulnaris reach the digits-metacarpals IV-V. We suggest that the crushing of the soil is accomplished by the two medial digits and that the lateral two digits mainly act as a remover or a sweeper of the crushed soil.
