Skull growth and variation in the Formosan wood mouse, Apodemus semotus
1992
Lin, L.K. (Kyushu Univ., Fukuoka (Japan). Faculty of Agriculture) | Shiraishi, S.
The skull growth and variation of Apodemus semotus were investigated using laboratory and field specimens. Among 15 skull characters, the largest and second largest growth rates on days 0-24 were for the nasal length. On days 25-50, the length-related characters (face) and mandible had relatively higher growth rates, but the width-related characters (braincase) were retarded in growth. The relative growth coefficient (alpha) against the condylobasal length was highest in the nasal length and height of mandible, and lowest in the interorbital breadth and breadth of occipital foramen. Relative ages of the field specimens were determined by age classes (I-VI) of tooth wear in laboratory specimens. Analyses of the skull variation in field specimens by univariate and multivariate techniques revealed that the greatest length had the lowest coefficient of variation with significant subsets which spanned age class II through VI, and had also the greatest loading on the first principal component. Comparison of skull growth in age class II (days 26-35) between laboratory and field conditions indicated that the field specimens had a stronger dorsal flexion of the anterior cranial base, and were longer in the lengths of mandible and lower molar series than were the laboratory specimens
显示更多 [+] 显示较少 [-]