Salivary glands of the Takin (Budorcas taxicolor, Mammalia, Bovidae) with special consideration of the Glandula zygomatica

The head of an adult male Takin (Budorcas taxicolor) was dissected with spe cial reference to the salivary glands. In addition, important parts of the facial musculature and the skull, the lacrimal bulla in particular, were in vestigated. The dissection was carried out on fresh material submerged in w ater. Consecutive dissection Steps were documented by a series of photograp hic slides and several proportional drawings. The ratio between the mass of the salivary glands and body mass for the Takin is slightly above the aver age value for the feeding type of a grass and roughage eater (GR). The morp hology of the salivary glands, the small size of the parotid gland in parti cular, support the classification of the Takin as GR with a tendency to the Intermediate feeding type (GR/IM). (Tendency to LM is further supported by the morphology of the digestive tract.) The ability to cope with a poorly digestible diet during the winter months may have been acquired as a preada ptation before the Takin's restriction to its present refuge habitats. Like the Japanese Serow (Capricornis crispus, Caprinae) and the Sai,oa-Ante lope (Saiga tatarica, Saiginae), the Takin possesses an additional compact salivary gland which so far has not been described, neither in the domestic nor in other free ranging ruminants investigated. According to its positio n as well as to the number and course of its excretory ducts this gland is the homologue of the glandula zygomatica of carnivores. Provided that this is correct the glandula zygomatica appears to be part of the basic plan of ruminants. Apparently it has been retained as a pie siomorphic character in only a few extant species. The partial or complete reduction of this salivary gland in the phylogeny o f the ruminants may have been caused by a change of feeding habits. However , the reduction may also result from the increasing separation of the orbit a from the temporal fossa narrowing the interspace where the glandula zygom atica is located. The separation serves to protect the ocular bulb from adv erse pressures effected by the masticatory musculature occurring particular ly in late evolved GR due to constant lateral grinding movements of the low er jaw during extensive rumination for particle size reduction.