准噶尔盆地南缘荒漠区大沙鼠和红尾沙鼠头骨特征比较OA

To investigate the differences in skull morphological characteristics and their relationship with body weight between the sympatric desert rodents Rhombomys opimus and Meriones libycus in the southern margin of the Junggar Basin,and to explore whether they exhibit convergent adaptations to the hyperarid and high-temperature desert environment,this study conducted a rodent community survey using the snap-trapping method in the desert region of the southern Junggar Basin,Xinjiang Uygur Autonomous Region.Thirteen skull morphological indices,including total skull length,basal length,median palatal length,zygomatic width,and least breadth between the orbits,were measured from captured specimens.The interspecific differences in skull traits and their correlations with body weight were analyzed.Results indicated that:1)Except for greatest length of the nasals(P=0.276),all 12 other skull indices exhibited highly significant interspecific differences(P<0.01);2)Among the 13 skull indices,only the length of the down tooth row of M.libycus showed a significant intraspecific sexual dimorphism(P<0.05),while other indices displayed no significant sex-based differences(P>0.05);3)Skull morphology trends relative to body weight revealed an extremely significantly positive correlation between profile length and body weight in R.opimus(R2=0.4808,P<0.01).For M.libycus,basal length(R²=0.3214),zygomatic breadth(R²=0.6020),and lower jaw length(R²=0.5656)exhibited extremely significant positive correlations with body weight(P<0.01).In conclusion,R.opimus and M.libycus display distinct interspecific differences in multiple skull traits.Notably,profile length in R.opimus,and basal length,zygomatic breadth,and total length in M.libycus showed continued growth into adulthood,while other traits lacked clear patterns.These findings supplement taxonomic and morphological data for both species and provide a reference for species identification and evolutionary studies.