No abstract

A description is given of the anatomy of the extrinsic and intrinsic muscles of the forelimb of the babirusa (Babyrousa babyrussa, L. 1758). Three adult animals, two males and a female were dissected and the results compared with the previously published information. Significant differences were found between the accounts, and these were analysed within the context of material availability and advances in anatomical nomenclature. Comparisons made with published descriptions of the pig (Sus scrofa) showed that the muscular anatomy of the two species is very similar. Four structures are present in the babirusa but not in the pig; the M. pronator teres is completely tendinous, a tendon branch from the Caput craniale m. extensor digitorum lateralis anastomoses with the tendon of the Caput intermedium m. extensor digitorum communis to the fourth digit, there is an additional small deep portion of the M. supraspinatus and a bundle of fibres from the M. pectoralis profundus inserts on the intersectio clavicularis. Four structures present in the pig but not the babirusa are an additional insertion from the M. cleido-occipitalis into the raphe of the neck, an extra medial insertion of the M. infraspinatus, the accessory tendinous origin of the M. flexor digitorum profundus and the ulnar head of the M. flexor carpi ulnaris.

A description is given of the anatomy of the muscles of the hindlimb of the babirusa (Babyrousa babyrussa L. 1758). Four adult animals, two males and two females were dissected and the results compared with previously published information. Significant differences were found between the accounts and these were analysed within the contexts of material availability and advances in anatomical nomenclature. Comparisons made with published descriptions of the pig (Sus scrofa) showed that the muscular anatomies of the two species are very similar. Those differences which are apparent, despite intraspecies variation in structure, include a thoracic vertebral origin for the M. psoas minor in babirusa but not pig, a smaller gluteal tongue to the M. gluteus medius in the babirusa, a failure of the Mm. gluteus medius to meet on the dorsal midline in the babirusa unlike the case in the pig, the two heads of the M. gluteus accessorius are of unequal size in the babirusa but not in the pig, the vertebral head of the M. obturatorius externus is absent in the babirusa and present in the pig.

The detailed muscular anatomy of the head of the Sulawesi Babirusa (Babyrousa celebensis) is described for the first time. The results show that the muscular anatomy of the Babyrousa is very similar to the pig genus Sus, despite long geological separation from it. Some differences were noted: the M. parietoauricularis was more clearly separated into two parts in the Babirusa than in the domestic pig; the rostral fibres of the M. levator anguli oculi reached the infraorbital sinus in the Babirusa but only as far as the medial corner of the eye in the domestic pig; the M. palatinus of the Babirusa is paired and did not reach the Os palatinum, unlike its description in the domestic pig and the Platysma pars zygomatica originates from the fascia of the neck in the Babirusa, whereas that of the domestic pig originates largely or entirely from the scapula.