Sexual dimorphism of craniodental morphology for Australian carnivorous marsupials (family Dasyuridae)

Sexual size dimorphism is widespread in mammals, often reflecting the influence of sexual selection and/or varied ecological pressures. In this study, we investigated the patterns and extent of sexual dimorphism in craniodental traits among adult dasyurid marsupials, with a primary focus on species in the subfamily Dasyurinae. This group spans a wide range of body sizes and ecological niches. Our research aimed to determine whether allometric scaling of cranial measurements differed between sexes and to assess the relationship between dimorphic traits and body size. We also explored whether sexual size dimorphism was associated with shape difference that might indicate complex functional adaptations. We analysed craniodental data to evaluate the predictive value of specific measurements for sex determination using a comparative approach across multiple dasyurid species. Our findings revealed that while sexual dimorphism was prevalent, particularly for larger species, it was not strictly correlated with body size. Shape dimorphism suggested the involvement of diet as a selective pressure, independent of size. We found that craniodental measurements could be used to discriminate between males and females for many, although not all, species but that the discriminating traits varied considerably between species. These results further our understanding of the interactions between morphology, sexual selection, and ecological roles in dasyurids, and provide important insights for interpreting the biology of both living and extinct mammalian carnivores.