AN OSTEOMETRICAL STUDY OF THE CRANIUM AND MANDIBLE OF THE LESSER MOUSE DEER (CHEVROTAIN), TRAGULUS-JAVANICUS

The lesser mouse deer (Tragulus javanicus) is one of the most primitiv e ruminants. Skulls of lesser mouse deer were measured to evaluate the ir growth. The age was estimated from the eruption and attrition of mo lars on the mandible. A total of 95 specimens was divided into five ag e groups, and the growth pattern in each sex was established for some measurements. The relative growth coefficients were calculated for the head and body length and several parts of the cranium and mandible ag ainst the profile length. Sexual dimorphism could not be found on the skull in any age group except for measurements related to the upper ca nine. However, females showed a higher value in head and body length i n the oldest group. This feature was consistent with an interpretation of mouse deer society as monogamous. Growth was more rapid in length than in width. Various statistical analyses showed that the visceral c ranium related to masticatory facility was much better developed than the neurocranium. However, observations on the shape of the mandible r amus and of the premolars implied that the masticatory function was no t suitable for taking roughage. This speculation agreed with previous reports on the feeding habits and digestive organs of the mouse deer.